JDBC连接数据库实例
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package javacommon.base;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class JDBCTemplate {
private Connection conn = null;
private Connection getConnection() {
if(conn == null) {
conn = DBManager.getConn();
}
return conn;
}
public JDBCTemplate(Connection conn) {
this.conn = conn;
}
public JDBCTemplate() {
conn = getConnection();
}
public Connection getConn() {
return conn;
}
public void beginTranscation() throws SQLException {
conn.setAutoCommit(false);
}
public void commit() throws SQLException {
conn.commit();
}
@SuppressWarnings("unchecked")
public List<Map> query(String sql, Object[] params) throws SQLException {
PreparedStatement pStmt = null;
ResultSet rSet = null;
List<Map> list = new ArrayList<Map>();
try {
pStmt = conn.prepareStatement(sql);
for (int i = 0; i < params.length; i++) {
pStmt.setObject(i + 1, params[i]);
}
rSet = pStmt.executeQuery();
ResultSetMetaData rsmd = rSet.getMetaData();
String[] names = new String[rsmd.getColumnCount()];
for (int i = 0; i < names.length; i++) {
names[i] = rsmd.getColumnName(i + 1);
}
while (rSet.next()) {
Map row = new HashMap();
for (int i = 0; i < names.length; i++) {
row.put(names[i], rSet.getObject(i + 1));
}
list.add(row);
}
} catch(SQLException e) {
e.printStackTrace();
throw e;
} finally {
if (rSet != null) {
try {
rSet.close();
} catch(SQLException e) {}
}
if (pStmt != null) {
try {
pStmt.close();
} catch(SQLException e) {}
}
}
return list;
}
public int insert(String sql, Object[] params) throws SQLException {
return executeUpdate(sql, params);
}
public int executeUpdate(String sql, Object[] params) throws SQLException {
PreparedStatement pStmt = null;
ResultSet rSet = null;
int result = 0;
try {
pStmt = conn.prepareStatement(sql);
for (int i = 0; i < params.length; i++) {
pStmt.setObject(i + 1, params[i]);
}
result = pStmt.executeUpdate();
} catch(SQLException e) {
e.printStackTrace();
throw e;
} finally {
if (pStmt != null) {
try {
pStmt.close();
} catch(SQLException e) {}
}
}
return result;
}
public void close() {
if (conn != null) {
DBManager.closeConn(conn);
}
}
}package javacommon.base;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.commons.dbcp.BasicDataSource;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* 数据库连接池管理类
* @author SN11631
*
*/
public class DBManager {
private static final Log LOG = LogFactory.getLog(DBManager.class);
private static DataSource dataSource;
static {
Properties properties = PropertiesHandler.readPropertiesFile("/opt/hr/hr-info-sync.properites");
try {
BasicDataSource basicDataSource = new BasicDataSource();
if (null != properties
.getProperty("dataSource.accessToUnderlyingConnectionAllowed")) {
basicDataSource
.setAccessToUnderlyingConnectionAllowed(Boolean.valueOf(properties
.getProperty("dataSource.accessToUnderlyingConnectionAllowed")));
}
// if (null !=
// properties.getProperty("dataSource.connectionInitSqls"))
// {basicDataSource.setConnectionInitSqls(properties.getProperty("dataSource.connectionInitSqls"));}
if (null != properties
.getProperty("dataSource.connectionProperties")) {
basicDataSource.setConnectionProperties(properties
.getProperty("dataSource.connectionProperties"));
}
if (null != properties.getProperty("dataSource.defaultAutoCommit")) {
basicDataSource.setDefaultAutoCommit(Boolean.valueOf(properties
.getProperty("dataSource.defaultAutoCommit")));
}
if (null != properties.getProperty("dataSource.defaultCatalog")) {
basicDataSource.setDefaultCatalog(properties
.getProperty("dataSource.defaultCatalog"));
}
if (null != properties.getProperty("dataSource.defaultReadOnly")) {
basicDataSource.setDefaultReadOnly(Boolean.valueOf(properties
.getProperty("dataSource.defaultReadOnly")));
}
if (null != properties
.getProperty("dataSource.defaultTransactionIsolation")) {
basicDataSource
.setDefaultTransactionIsolation(Integer.valueOf(properties
.getProperty("dataSource.defaultTransactionIsolation")));
}
// if (null !=
// properties.getProperty("dataSource.driverClassLoader"))
// {basicDataSource.setDriverClassLoader(properties.getProperty("dataSource.driverClassLoader"));}
if (null != properties.getProperty("dataSource.driverClassName")) {
basicDataSource.setDriverClassName(properties
.getProperty("dataSource.driverClassName"));
}
if (null != properties.getProperty("dataSource.initialSize")) {
basicDataSource.setInitialSize(Integer.valueOf(properties
.getProperty("dataSource.initialSize")));
}
if (null != properties.getProperty("dataSource.logAbandoned")) {
basicDataSource.setLogAbandoned(Boolean.valueOf(properties
.getProperty("dataSource.logAbandoned")));
}
if (null != properties.getProperty("dataSource.loginTimeout")) {
basicDataSource.setLoginTimeout(Integer.valueOf(properties
.getProperty("dataSource.loginTimeout")));
}
// if (null != properties.getProperty("dataSource.logWriter"))
// {basicDataSource.setLogWriter(properties.getProperty("dataSource.logWriter"));}
if (null != properties.getProperty("dataSource.maxActive")) {
basicDataSource.setMaxActive(Integer.valueOf(properties
.getProperty("dataSource.maxActive")));
}
if (null != properties.getProperty("dataSource.maxIdle")) {
basicDataSource.setMaxIdle(Integer.valueOf(properties
.getProperty("dataSource.maxIdle")));
}
if (null != properties
.getProperty("dataSource.maxOpenPreparedStatements")) {
basicDataSource
.setMaxOpenPreparedStatements(Integer.valueOf(properties
.getProperty("dataSource.maxOpenPreparedStatements")));
}
if (null != properties.getProperty("dataSource.maxWait")) {
basicDataSource.setMaxWait(Long.valueOf(properties
.getProperty("dataSource.maxWait")));
}
if (null != properties
.getProperty("dataSource.minEvictableIdleTimeMillis")) {
basicDataSource
.setMinEvictableIdleTimeMillis(Long.valueOf(properties
.getProperty("dataSource.minEvictableIdleTimeMillis")));
}
if (null != properties.getProperty("dataSource.minIdle")) {
basicDataSource.setMinIdle(Integer.valueOf(properties
.getProperty("dataSource.minIdle")));
}
if (null != properties
.getProperty("dataSource.numTestsPerEvictionRun")) {
basicDataSource
.setNumTestsPerEvictionRun(Integer.valueOf(properties
.getProperty("dataSource.numTestsPerEvictionRun")));
}
if (null != properties.getProperty("dataSource.password")) {
basicDataSource.setPassword(properties
.getProperty("dataSource.password"));
}
if (null != properties
.getProperty("dataSource.poolPreparedStatements")) {
basicDataSource
.setPoolPreparedStatements(Boolean.valueOf(properties
.getProperty("dataSource.poolPreparedStatements")));
}
if (null != properties.getProperty("dataSource.removeAbandoned")) {
basicDataSource.setRemoveAbandoned(Boolean.valueOf(properties
.getProperty("dataSource.removeAbandoned")));
}
if (null != properties
.getProperty("dataSource.removeAbandonedTimeout")) {
basicDataSource
.setRemoveAbandonedTimeout(Integer.valueOf(properties
.getProperty("dataSource.removeAbandonedTimeout")));
}
if (null != properties.getProperty("dataSource.testOnBorrow")) {
basicDataSource.setTestOnBorrow(Boolean.valueOf(properties
.getProperty("dataSource.testOnBorrow")));
}
if (null != properties.getProperty("dataSource.testOnReturn")) {
basicDataSource.setTestOnReturn(Boolean.valueOf(properties
.getProperty("dataSource.testOnReturn")));
}
if (null != properties.getProperty("dataSource.testWhileIdle")) {
basicDataSource.setTestWhileIdle(Boolean.valueOf(properties
.getProperty("dataSource.testWhileIdle")));
}
if (null != properties
.getProperty("dataSource.timeBetweenEvictionRunsMillis")) {
basicDataSource
.setTimeBetweenEvictionRunsMillis(Long.valueOf(properties
.getProperty("dataSource.timeBetweenEvictionRunsMillis")));
}
if (null != properties.getProperty("dataSource.url")) {
basicDataSource
.setUrl(properties.getProperty("dataSource.url"));
}
if (null != properties.getProperty("dataSource.username")) {
basicDataSource.setUsername(properties
.getProperty("dataSource.username"));
}
if (null != properties.getProperty("dataSource.validationQuery")) {
basicDataSource.setValidationQuery(properties
.getProperty("dataSource.validationQuery"));
}
if (null != properties
.getProperty("dataSource.validationQueryTimeout")) {
basicDataSource
.setValidationQueryTimeout(Integer.valueOf(properties
.getProperty("dataSource.validationQueryTimeout")));
}
dataSource = basicDataSource;
Connection conn = getConn();
DatabaseMetaData mdm = conn.getMetaData();
LOG.info("Connected to " + mdm.getDatabaseProductName() + " "
+ mdm.getDatabaseProductVersion());
if (conn != null) {
conn.close();
}
} catch (Exception e) {
LOG.error("初始化连接池失败：" + e);
}
}
/**
* 获取链接，用完后记得关闭
* @see {@link DBManager#closeConn(Connection)}
* @return
*/
public static final Connection getConn() {
Connection conn = null;
try {
conn = dataSource.getConnection();
} catch (SQLException e) {
LOG.error("获取数据库连接失败：" + e);
}
return conn;
}
/**
* 关闭连接
*
* @param conn
* 需要关闭的连接
*/
public static void closeConn(Connection conn) {
try {
if (conn != null && !conn.isClosed()) {
conn.setAutoCommit(true);
conn.close();
}
} catch (SQLException e) {
LOG.error("关闭数据库连接失败：" + e);
}
}
}package javacommon.base;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
/**
* Properties处理
* @author SN11631
*
*/
public class PropertiesHandler {
/**
* 读取资源文件
* @param filename 文件名
* @return Properties
*/
public static Properties readPropertiesFile(String filename)
{
Properties properties = new Properties();
try
{
InputStream inputStream = new FileInputStream(filename);
properties.load(inputStream);
inputStream.close(); //关闭流
}
catch (IOException e)
{
e.printStackTrace();
}
return properties;
}
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