JPA J2SE 桌面应用范例

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JPA虽然是Java EE规范的一部分,但是可以在J2SE环境下单独使用,不需要Web相关容器。本篇主要通过Netbeans 自动生成的代码来学习JPA相关内容。

1.打开Netbeans 8.1 添加mysql数据库连接

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2.新建Java应用程式,输入项目名称JpaExample

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3.在项目中右键新建其他,选择主样例窗体/详细样例窗体,输入类名称和包名称

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4.选择第一步建立的数据库连接->选择表(user),右侧为程式中用到的栏位,默认是全部带到右边,不需要的可以移到左边

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5.选择在Swing界面上显示的栏位,默认全部在右边表示全选,不需要的可以移到左边。点击完成

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6.查看生成的类,persistence.xml是jpa配置文件,User.java是对于table的实体,MasterDetailForm.java是自动生成的Swing界面,自动添加的库文件包括实现JPA2.1 的EclipseLink和添加连接mysql数据库的jdbc驱动,都是安装Netbeans自带的可以自行替换指定版本。 

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7.运行,点击New就可以新增内容,Delete删除上面Jtable选中的数据,Save保存到数据库,Refresh 刷新数据,主要是数据库数据与JPA同步,如果数据库有变动,刷新后本地JPA显示变动后数据。

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8.代码分析,完整MasterDetailForm.java如下。

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package com.cc.jpa;

import java.awt.EventQueue;
import java.beans.Beans;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.RollbackException;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 *
 * @author dev
 */
public class MasterDetailForm extends JPanel {
    
    public MasterDetailForm() {
        initComponents();
        if (!Beans.isDesignTime()) {
            entityManager.getTransaction().begin();
        }
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {
        bindingGroup = new org.jdesktop.beansbinding.BindingGroup();

        entityManager = java.beans.Beans.isDesignTime() ? null : javax.persistence.Persistence.createEntityManagerFactory("ccPU").createEntityManager();
        query = java.beans.Beans.isDesignTime() ? null : entityManager.createQuery("SELECT u FROM User u");
        list = java.beans.Beans.isDesignTime() ? java.util.Collections.emptyList() : org.jdesktop.observablecollections.ObservableCollections.observableList(query.getResultList());
        masterScrollPane = new javax.swing.JScrollPane();
        masterTable = new javax.swing.JTable();
        idLabel = new javax.swing.JLabel();
        usernmaeLabel = new javax.swing.JLabel();
        passwordLabel = new javax.swing.JLabel();
        nameLabel = new javax.swing.JLabel();
        idField = new javax.swing.JTextField();
        usernmaeField = new javax.swing.JTextField();
        passwordField = new javax.swing.JTextField();
        nameField = new javax.swing.JTextField();
        saveButton = new javax.swing.JButton();
        refreshButton = new javax.swing.JButton();
        newButton = new javax.swing.JButton();
        deleteButton = new javax.swing.JButton();

        FormListener formListener = new FormListener();

        org.jdesktop.swingbinding.JTableBinding jTableBinding = org.jdesktop.swingbinding.SwingBindings.createJTableBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ_WRITE, list, masterTable);
        org.jdesktop.swingbinding.JTableBinding.ColumnBinding columnBinding = jTableBinding.addColumnBinding(org.jdesktop.beansbinding.ELProperty.create("${id}"));
        columnBinding.setColumnName("Id");
        columnBinding.setColumnClass(Integer.class);
        columnBinding = jTableBinding.addColumnBinding(org.jdesktop.beansbinding.ELProperty.create("${usernmae}"));
        columnBinding.setColumnName("Usernmae");
        columnBinding.setColumnClass(String.class);
        columnBinding = jTableBinding.addColumnBinding(org.jdesktop.beansbinding.ELProperty.create("${password}"));
        columnBinding.setColumnName("Password");
        columnBinding.setColumnClass(String.class);
        columnBinding = jTableBinding.addColumnBinding(org.jdesktop.beansbinding.ELProperty.create("${name}"));
        columnBinding.setColumnName("Name");
        columnBinding.setColumnClass(String.class);
        bindingGroup.addBinding(jTableBinding);

        masterScrollPane.setViewportView(masterTable);

        idLabel.setText("Id:");

        usernmaeLabel.setText("Usernmae:");

        passwordLabel.setText("Password:");

        nameLabel.setText("Name:");

        org.jdesktop.beansbinding.Binding binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ_WRITE, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement.id}"), idField, org.jdesktop.beansbinding.BeanProperty.create("text"));
        binding.setSourceUnreadableValue("null");
        bindingGroup.addBinding(binding);
        binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement != null}"), idField, org.jdesktop.beansbinding.BeanProperty.create("enabled"));
        bindingGroup.addBinding(binding);

        binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ_WRITE, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement.usernmae}"), usernmaeField, org.jdesktop.beansbinding.BeanProperty.create("text"));
        binding.setSourceUnreadableValue("null");
        bindingGroup.addBinding(binding);
        binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement != null}"), usernmaeField, org.jdesktop.beansbinding.BeanProperty.create("enabled"));
        bindingGroup.addBinding(binding);

        binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ_WRITE, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement.password}"), passwordField, org.jdesktop.beansbinding.BeanProperty.create("text"));
        binding.setSourceUnreadableValue("null");
        bindingGroup.addBinding(binding);
        binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement != null}"), passwordField, org.jdesktop.beansbinding.BeanProperty.create("enabled"));
        bindingGroup.addBinding(binding);

        binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ_WRITE, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement.name}"), nameField, org.jdesktop.beansbinding.BeanProperty.create("text"));
        binding.setSourceUnreadableValue("null");
        bindingGroup.addBinding(binding);
        binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement != null}"), nameField, org.jdesktop.beansbinding.BeanProperty.create("enabled"));
        bindingGroup.addBinding(binding);

        saveButton.setText("Save");
        saveButton.addActionListener(formListener);

        refreshButton.setText("Refresh");
        refreshButton.addActionListener(formListener);

        newButton.setText("New");
        newButton.addActionListener(formListener);

        deleteButton.setText("Delete");

        binding = org.jdesktop.beansbinding.Bindings.createAutoBinding(org.jdesktop.beansbinding.AutoBinding.UpdateStrategy.READ, masterTable, org.jdesktop.beansbinding.ELProperty.create("${selectedElement != null}"), deleteButton, org.jdesktop.beansbinding.BeanProperty.create("enabled"));
        bindingGroup.addBinding(binding);

        deleteButton.addActionListener(formListener);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addComponent(newButton)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(deleteButton)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(refreshButton)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(saveButton)
                .addContainerGap())
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(idLabel)
                    .addComponent(usernmaeLabel)
                    .addComponent(passwordLabel)
                    .addComponent(nameLabel))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(idField, javax.swing.GroupLayout.DEFAULT_SIZE, 315, Short.MAX_VALUE)
                    .addComponent(usernmaeField, javax.swing.GroupLayout.DEFAULT_SIZE, 315, Short.MAX_VALUE)
                    .addComponent(passwordField, javax.swing.GroupLayout.DEFAULT_SIZE, 315, Short.MAX_VALUE)
                    .addComponent(nameField, javax.swing.GroupLayout.DEFAULT_SIZE, 315, Short.MAX_VALUE))
                .addContainerGap())
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(masterScrollPane, javax.swing.GroupLayout.DEFAULT_SIZE, 380, Short.MAX_VALUE)
                .addContainerGap())
        );

        layout.linkSize(javax.swing.SwingConstants.HORIZONTAL, new java.awt.Component[] {deleteButton, newButton, refreshButton, saveButton});

        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(masterScrollPane, javax.swing.GroupLayout.DEFAULT_SIZE, 130, Short.MAX_VALUE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(idLabel)
                    .addComponent(idField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(usernmaeLabel)
                    .addComponent(usernmaeField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(passwordLabel)
                    .addComponent(passwordField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(nameLabel)
                    .addComponent(nameField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(saveButton)
                    .addComponent(refreshButton)
                    .addComponent(deleteButton)
                    .addComponent(newButton))
                .addContainerGap())
        );

        bindingGroup.bind();
    }

    // Code for dispatching events from components to event handlers.

    private class FormListener implements java.awt.event.ActionListener {
        FormListener() {}
        public void actionPerformed(java.awt.event.ActionEvent evt) {
            if (evt.getSource() == saveButton) {
                MasterDetailForm.this.saveButtonActionPerformed(evt);
            }
            else if (evt.getSource() == refreshButton) {
                MasterDetailForm.this.refreshButtonActionPerformed(evt);
            }
            else if (evt.getSource() == newButton) {
                MasterDetailForm.this.newButtonActionPerformed(evt);
            }
            else if (evt.getSource() == deleteButton) {
                MasterDetailForm.this.deleteButtonActionPerformed(evt);
            }
        }
    }// </editor-fold>                        

    
    @SuppressWarnings("unchecked")
    private void refreshButtonActionPerformed(java.awt.event.ActionEvent evt) {                                              
        entityManager.getTransaction().rollback();
        entityManager.getTransaction().begin();
        java.util.Collection data = query.getResultList();
        for (Object entity : data) {
            entityManager.refresh(entity);
        }
        list.clear();
        list.addAll(data);
    }                                             

    private void deleteButtonActionPerformed(java.awt.event.ActionEvent evt) {                                             
        int[] selected = masterTable.getSelectedRows();
        List<com.cc.jpa.User> toRemove = new ArrayList<com.cc.jpa.User>(selected.length);
        for (int idx = 0; idx < selected.length; idx++) {
            com.cc.jpa.User u = list.get(masterTable.convertRowIndexToModel(selected[idx]));
            toRemove.add(u);
            entityManager.remove(u);
        }
        list.removeAll(toRemove);
    }                                            

    private void newButtonActionPerformed(java.awt.event.ActionEvent evt) {                                          
        com.cc.jpa.User u = new com.cc.jpa.User();
        entityManager.persist(u);
        list.add(u);
        int row = list.size() - 1;
        masterTable.setRowSelectionInterval(row, row);
        masterTable.scrollRectToVisible(masterTable.getCellRect(row, 0, true));
    }                                         
    
    private void saveButtonActionPerformed(java.awt.event.ActionEvent evt) {                                           
        try {
            entityManager.getTransaction().commit();
            entityManager.getTransaction().begin();
        } catch (RollbackException rex) {
            rex.printStackTrace();
            entityManager.getTransaction().begin();
            List<com.cc.jpa.User> merged = new ArrayList<com.cc.jpa.User>(list.size());
            for (com.cc.jpa.User u : list) {
                merged.add(entityManager.merge(u));
            }
            list.clear();
            list.addAll(merged);
        }
    }                                          


    // Variables declaration - do not modify                     
    private javax.swing.JButton deleteButton;
    private javax.persistence.EntityManager entityManager;
    private javax.swing.JTextField idField;
    private javax.swing.JLabel idLabel;
    private java.util.List<com.cc.jpa.User> list;
    private javax.swing.JScrollPane masterScrollPane;
    private javax.swing.JTable masterTable;
    private javax.swing.JTextField nameField;
    private javax.swing.JLabel nameLabel;
    private javax.swing.JButton newButton;
    private javax.swing.JTextField passwordField;
    private javax.swing.JLabel passwordLabel;
    private javax.persistence.Query query;
    private javax.swing.JButton refreshButton;
    private javax.swing.JButton saveButton;
    private javax.swing.JTextField usernmaeField;
    private javax.swing.JLabel usernmaeLabel;
    private org.jdesktop.beansbinding.BindingGroup bindingGroup;
    // End of variables declaration                   
    public static void main(String[] args) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(MasterDetailForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(MasterDetailForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(MasterDetailForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(MasterDetailForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame();
                frame.setContentPane(new MasterDetailForm());
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.pack();
                frame.setVisible(true);
            }
        });
    }
    
}
View Code

主要部分:

entityManager初始化,ccPU是在persistence.xml中定义的persistence-unit 的名称, query 和list的 代码 一个是新建一个查询,另一个是查出所有资料。query其实可以用另一种写法,使用entityManager.createNamedQuery("User.findAll");

查看User.java文件会发现,Netbeans 生成的文件里面默认生成了几个Query,也可以根据需要自行添加,集中管理。

entityManager = java.beans.Beans.isDesignTime() ? null : javax.persistence.Persistence.createEntityManagerFactory("ccPU").createEntityManager();
query = java.beans.Beans.isDesignTime() ? null : entityManager.createQuery("SELECT u FROM User u");
list = java.beans.Beans.isDesignTime() ? java.util.Collections.emptyList() : org.jdesktop.observablecollections.ObservableCollections.observableList(query.getResultList());

User:

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/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package com.cc.jpa;

import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.io.Serializable;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.persistence.Transient;

/**
 *
 * @author dev
 */
@Entity
@Table(name = "user", catalog = "cc", schema = "")
@NamedQueries({
    @NamedQuery(name = "User.findAll", query = "SELECT u FROM User u"),
    @NamedQuery(name = "User.findById", query = "SELECT u FROM User u WHERE u.id = :id"),
    @NamedQuery(name = "User.findByUsernmae", query = "SELECT u FROM User u WHERE u.usernmae = :usernmae"),
    @NamedQuery(name = "User.findByPassword", query = "SELECT u FROM User u WHERE u.password = :password"),
    @NamedQuery(name = "User.findByName", query = "SELECT u FROM User u WHERE u.name = :name")})
public class User implements Serializable {

    @Transient
    private PropertyChangeSupport changeSupport = new PropertyChangeSupport(this);

    private static final long serialVersionUID = 1L;
    @Id
    @Basic(optional = false)
    @Column(name = "id")
    private Integer id;
    @Basic(optional = false)
    @Column(name = "usernmae")
    private String usernmae;
    @Basic(optional = false)
    @Column(name = "password")
    private String password;
    @Basic(optional = false)
    @Column(name = "name")
    private String name;

    public User() {
    }

    public User(Integer id) {
        this.id = id;
    }

    public User(Integer id, String usernmae, String password, String name) {
        this.id = id;
        this.usernmae = usernmae;
        this.password = password;
        this.name = name;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        Integer oldId = this.id;
        this.id = id;
        changeSupport.firePropertyChange("id", oldId, id);
    }

    public String getUsernmae() {
        return usernmae;
    }

    public void setUsernmae(String usernmae) {
        String oldUsernmae = this.usernmae;
        this.usernmae = usernmae;
        changeSupport.firePropertyChange("usernmae", oldUsernmae, usernmae);
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        String oldPassword = this.password;
        this.password = password;
        changeSupport.firePropertyChange("password", oldPassword, password);
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        String oldName = this.name;
        this.name = name;
        changeSupport.firePropertyChange("name", oldName, name);
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won‘t work in the case the id fields are not set
        if (!(object instanceof User)) {
            return false;
        }
        User other = (User) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "com.cc.jpa.User[ id=" + id + " ]";
    }

    public void addPropertyChangeListener(PropertyChangeListener listener) {
        changeSupport.addPropertyChangeListener(listener);
    }

    public void removePropertyChangeListener(PropertyChangeListener listener) {
        changeSupport.removePropertyChangeListener(listener);
    }
    
}
View Code

New,主要是新增一个新的User对象,没有写到数据库中,主要是前端操作

com.cc.jpa.User u = new com.cc.jpa.User();
entityManager.persist(u);
list.add(u);
int row = list.size() - 1;
masterTable.setRowSelectionInterval(row, row);
masterTable.scrollRectToVisible(masterTable.getCellRect(row, 0, true));

Delete,执行entityManager.remove(u)并没有写到数据库是因为有开启Transaction ,在保存的时候才会commit

int[] selected = masterTable.getSelectedRows(); 
List<com.cc.jpa.User> toRemove = new ArrayList<com.cc.jpa.User>(selected.length); for (int idx = 0; idx < selected.length; idx++) { com.cc.jpa.User u = list.get(masterTable.convertRowIndexToModel(selected[idx])); toRemove.add(u); entityManager.remove(u); } list.removeAll(toRemove);

Save,主要就是Transaction 的提交以及异常处理

try {
entityManager.getTransaction().commit();
entityManager.getTransaction().begin();
} catch (RollbackException rex) {
rex.printStackTrace();
entityManager.getTransaction().begin();
List<com.cc.jpa.User> merged = new ArrayList<com.cc.jpa.User>(list.size());
for (com.cc.jpa.User u : list) {
merged.add(entityManager.merge(u));
}
list.clear();
list.addAll(merged);
}

Refresh,同步数据库数据

entityManager.getTransaction().rollback();
entityManager.getTransaction().begin();
java.util.Collection data = query.getResultList();
for (Object entity : data) {
    entityManager.refresh(entity);
}
list.clear();
list.addAll(data);

 

此范例主要是J2SE 下JPA的使用,实际项目中,可能设计很多table,程式也会相应的分层,如果只是学习一下JPA的特性熟悉下方法,这种方式也是没问题的。使用eclipse 创建JPA时 EclipseLink 需要单独下载,EclipseLink 前身是Oracle TopLink ,以前商业框架 ADF的一部分,用JPA 选择EclipseLink ,Hibernate 或其他实现都没有关系,而且只用JPA的功能,不用实现提供的一些扩展的话,切换使用都是没有问题的,就像JSP页面用不同的容器,Tomcat、Jetty、GlassFish结果是没差别的。

 

 

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