Java中如何使用JSON-lib包解析Json格式呢?

 JSON-lib包可以将一个beans,collections,maps,java arrays,XML和JSON互相转换
   可以将Java对象转成json格式的字符串
   也可以将Java对象转换成xml格式的文档
   同样可以将json字符串转换成Java对象
    或将xml字符串转换成Java对象
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JSON-lib包下载地址
 http://json-lib.sourceforge.net/

格式转换方法

list集合转换成json方法

List list = new ArrayList();
list.add( "aaa" );
list.add( "bbb" );
JSONArray jsonArray2 = JSONArray.fromObject( list );

Map集合转换成json方法

Map map = new HashMap();
map.put("name", "json");
map.put("bool", Boolean.TRUE);
map.put("int", new Integer(1));
map.put("arr", new String[] { "a", "b" });
map.put("func", "function(i){ return this.arr[i]; }");
JSONObject json = JSONObject.fromObject(map);

Bean转换成json方法

JSONObject jsonObject = JSONObject.fromObject(new JsonBean());

数组转换成json方法

boolean[] boolArray = new boolean[] { true, false, true };
JSONArray jsonArray1 = JSONArray.fromObject(boolArray);

字符串转换成json方法

JSONArray jsonArray3 = JSONArray.fromObject("['json','is','easy']" );

beans转换成json方法

List list = new ArrayList();
JsonBean2 jb1 = new JsonBean2();
jb1.setCol(1);
jb1.setRow(1);
jb1.setValue("aaa");

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

list.add(jb1);
list.add(jb2);
JSONArray ja = JSONArray.fromObject(list);

JSONObject转换DynaBean方法

String json = "{name=\"json\",bool:true,int:1,double:2.2}";
JSONObject jsonObject = JSONObject.fromObject(json);
//抽象的写法：DynaBean bean = (DynaBean) JSONSerializer.toJava( jsonObject );   
Object bean = JSONObject.toBean(jsonObject);
//Object bean1 = JSONSerializer.toJava(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"));

JSONObject转换JavaBean方法

String json = "{name:\"zhangsan\",age:25,hight:1.72,sex:true}";
JSONObject jsonObject = JSONObject.fromObject(json);
UserBean bean = (UserBean) JSONObject.toBean(jsonObject, UserBean.class);
System.out.println(jsonObject);

JSONArray转换List方法

String json = "[\"first\",\"second\"]";
JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON(json);
List output = (List) JSONSerializer.toJava(jsonArray);

JSONArray转换array方法

String json = "[\"first\",\"second\"]";
JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON(json);
JsonConfig jsonConfig = new JsonConfig();
jsonConfig.setArrayMode(JsonConfig.MODE_OBJECT_ARRAY);
Object[] output = (Object[]) JSONSerializer.toJava(jsonArray, jsonConfig);
Object[] expected = new Object[] { "first", "second" };
ArrayAssertions.assertEquals(expected, output);

Arrays转换Json方法

@Test
public void array2json() {
    int[] intArray = new int[] {
        1,
        4,
        5
    };
    JSONArray jsonArray1 = JSONArray.fromObject(intArray);
    System.out.println("int[] intArray");
    System.out.println(jsonArray1);
    boolean[] boolArray = new boolean[] {
        true,
        false,
        true
    };
    System.out.println("boolean[] boolArray");
    JSONArray jsonArray2 = JSONArray.fromObject(boolArray);
    System.out.println(jsonArray2);
    int[][] int2Array = new int[][] {
        {
            1,
            2
        },
        {
            3,
            4
        }
    };
    JSONArray jsonArray3 = JSONArray.fromObject(int2Array);
    System.out.println("int[][] int2Array");
    System.out.println(jsonArray3);
    float[] floatArray = new float[] {
        0.1f,
        0.2f,
        0.3f
    };
    JSONArray jsonArray4 = JSONArray.fromObject(floatArray);
    System.out.println("float[] floatArray");
    System.out.println(jsonArray4);
    String[] strArray = new String[] {
        "xiaoxiao",
        "liuliu",
        "zhangzhang"
    };
    JSONArray jsonArray5 = JSONArray.fromObject(strArray);
    System.out.println("String[] strArray");
    System.out.println(jsonArray5);
} 

Collections转换Json方法

@Test
public void collections2json() {
    List list1 = new ArrayList();
    list1.add("first");
    list1.add("second");
    JSONArray jsonArray1 = JSONArray.fromObject(list1);
    System.out.println("List list1");
    System.out.println(jsonArray1);
    List < User > list2 = new ArrayList < User > ();
    list2.add(new User("xiaoming", "男", 6));
    list2.add(new User("xiaozhang", "女", 7));
    list2.add(new User("xiaoliu", "男", 8));
    JSONArray jsonArray2 = JSONArray.fromObject(list2);
    System.out.println("List<User> list2");
    System.out.println(jsonArray2);
}
 

Xml转换Json方法

@Test
public void xml2json() {
    String s = "<user>
                        <name id='1'>xiaoxiao</name>
                        <sex class='s1'>男</sex>
                        <age>6</age>
                    </user>";
    XMLSerializer x = new XMLSerializer();
    JSON json = x.read(s);
    System.out.println("XmlToJson");
    System.out.println(json.toString());
}