json数组转java对象怎么转？

Posted 2023-03-29

json数组转java对象怎么转？

1、需要json的相关jar包

2、设置json格式字符串：

String str="\"student\":[\"name\":\"leilei\",\"age\":23,\"name\":\"leilei02\",\"age\":23]";

3、建立相应的类：

public class StudentList
List<Student> student;
public List<Student> getStudent()
return student;


public void setStudent(List<Student> student)
this.student = student;



public class Student
private String name;
private int age;
//private StudentClass studentClass;
public String getName()
return name;

public void setName(String name)
this.name = name;

public int getAge()
return age;

public void setAge(int age)
this.age = age;



4、测试程序

import java.util.List;
import org.codehaus.jackson.map.ObjectMapper;

public class JsonToJavaBean
public static void main(String[] args)
String str="\"student\":[\"name\":\"leilei\",\"age\":23,\"name\":\"leilei02\",\"age\":23]";
Student stu = null;
List<Student> list = null;
try
ObjectMapper objectMapper=new ObjectMapper();
StudentList studentList=objectMapper.readValue(str, StudentList.class);
list=studentList.getStudent();
catch (Exception e)
// TODO Auto-generated catch block
e.printStackTrace();

for(Student s:list)
System.out.println(s.getName());

参考技术A 看别人的：
/**
* 从一个JSON数组得到一个java对象数组，形如：
* ["id" : idValue, "name" : nameValue, "id" : idValue, "name" : nameValue, ...]
* @param object
* @param clazz
* @return
*/
public static Object[] getDTOArray(String jsonString, Class clazz)
setDataFormat2JAVA();
JSONArray array = JSONArray.fromObject(jsonString);
Object[] obj = new Object[array.size()];
for(int i = 0; i < array.size(); i++)
JSONObject jsonObject = array.getJSONObject(i);
obj[i] = JSONObject.toBean(jsonObject, clazz);

return obj;
参考技术B 如果你的json数组是字符串格式，可以使用
JSONObject obj = JSONObject.fromString(jsonStr);
然后你查看JSONObject 的api方法，它里面有getJSONArray()的方法，转数组。

java对象怎么转json数组 跪求啊

JSON-lib这个Java类包用于把bean,map和XML转换成JSON并能够把JSON转回成bean和DynaBean。

下载地址:http://json-lib.sourceforge.net/
还要需要的第3方包:
org.apache.commons(3.2以上版本)
org.apache.oro
net.sf.ezmorph(ezmorph-1.0.4.jar)
nu.xom

1、List
Java代码
boolean[] boolArray =newboolean[]true,false,true;
JSONArray jsonArray1 = JSONArray.fromObject( boolArray );
System.out.println( jsonArray1 );
// prints [true,false,true]

List list =newArrayList();
list.add("first");
list.add("second");
JSONArray jsonArray2 = JSONArray.fromObject( list );
System.out.println( jsonArray2 );
// prints ["first","second"]

JSONArray jsonArray3 = JSONArray.fromObject("['json','is','easy']");
System.out.println( jsonArray3 );
// prints ["json","is","easy"]

2、Map
Java代码
Map map =newHashMap();
map.put("name","json");
map.put("bool", Boolean.TRUE );

map.put("int",newInteger(1) );
map.put("arr",newString[]"a","b" );
map.put("func","function(i) return this.arr[i]; ");
JSONObject json = JSONObject.fromObject( map );
System.out.println( json );
//"func":function(i) return this.arr[i]; ,"arr":["a","b"],"int":1,"name":"json","bool":true

3、BEAN
Java代码
/**
* Bean.java
private String name = "json";
private int pojoId = 1;
private char[] ptions = new char[]'a','f';
private String func1 = "function(i) return this.options[i]; ";
private JSONFunction func2 = new JSONFunction(new String[]"i","return this.options[i];");
*/
JSONObject jsonObject = JSONObject.fromObject(newJsonBean() );
System.out.println( jsonObject );
//"func1":function(i) return this.options[i]; ,"pojoId":1,"name":"json","options":["a","f"],"func2":function(i) return this.options[i];

4、BEANS
Java代码
/**
* private int row ;
private int col ;
private String value ;
*
*/
List list =newArrayList();
JsonBean2 jb1 =newJsonBean2();
jb1.setCol(1);
jb1.setRow(1);
jb1.setValue("xx");

JsonBean2 jb2 =newJsonBean2();
jb2.setCol(2);
jb2.setRow(2);
jb2.setValue("");

list.add(jb1);
list.add(jb2);

JSONArray ja = JSONArray.fromObject(list);
System.out.println( ja.toString() );
//["value":"xx","row":1,"col":1,"value":"","row":2,"col":2]

5、String to bean
Java代码
String json ="name=\"json\",bool:true,int:1,double:2.2,func:function(a) return a; ,array:[1,2]";
JSONObject jsonObject = JSONObject.fromString(json);
Object bean = JSONObject.toBean( jsonObject );
assertEquals( jsonObject.get("name"), PropertyUtils.getProperty( bean,"name") );
assertEquals( jsonObject.get("bool"), PropertyUtils.getProperty( bean,"bool") );
assertEquals( jsonObject.get("int"), PropertyUtils.getProperty( bean,"int") );
assertEquals( jsonObject.get("double"), PropertyUtils.getProperty( bean,"double") );
assertEquals( jsonObject.get("func"), PropertyUtils.getProperty( bean,"func") );
List expected = JSONArray.toList( jsonObject.getJSONArray("array") );
assertEquals( expected, (List) PropertyUtils.getProperty( bean,"array") );

Java代码
String json ="\"value\":\"xx\",\"row\":1,\"col\":1";
JSONObject jsonObject = JSONObject.fromString(json);
JsonBean2 bean = (JsonBean2) JSONObject.toBean( jsonObject, JsonBean2.class);
assertEquals( jsonObject.get("col"),newInteger( bean.getCol()) );
assertEquals( jsonObject.get("row"),newInteger( bean.getRow() ) );
assertEquals( jsonObject.get("value"), bean.getValue() );

6 json to xml
1)
JSONObject json = new JSONObject( true );
String xml = XMLSerializer.write( json );

<o class="object" null="true">

2)
JSONObject json = JSONObject.fromObject("\"name\":\"json\",\"bool\":true,\"int\":1");
String xml = XMLSerializer.write( json );
<o class="object">
<name type="string">json</name>
<bool type="boolean">true</bool>
<int type="number">1</int>
</o>
<o class="object">
<name type="string">json</name>
<bool type="boolean">true</bool>
<int type="number">1</int>
</o>
3)
JSONArray json = JSONArray.fromObject("[1,2,3]");
String xml = XMLSerializer.write( json );
<a class="array">
<e type="number">1</e>
<e type="number">2</e>
<e type="number">3</e>
</a>

7 、xml to json
<a class="array">
<e type="function" params="i,j">
return matrix[i][j];
</e>
</a>
<a class="array">
<e type="function" params="i,j">
return matrix[i][j];
</e>
</a>

JSONArray json = (JSONArray) XMLSerializer.read( xml );
System.out.println( json );
// prints [function(i,j) return matrix[i][j]; ] 参考技术A 自己写程序抽取java对象中的数据保存在一个json字符串中，在通过js中eval 方法编译json字符串成相应的对象。