这一部分主要讲解使用json-lib包将java数据类型转换成json的数据类型,也就是java——>json。
首先介绍JSONSerializer,它使用i简单干净的接口方式将任何java与json直接进行转换,java——>json,使用JSONSerializer.toJSON(),json——>java 使用toJava()。
1 // 将string转换成json 2 String s1 = new String("{1:1}"); 3 String s2 = new String("[1,1]"); 4 JSONObject json1 = (JSONObject) JSONSerializer.toJSON(s1); 5 System.out.println("——用JSONSerializer将string转换json——" + json1); 6 JSONArray json2 = (JSONArray) JSONSerializer.toJSON(s2); 7 System.out.println("——用JSONSerializer将string转换jsonArray——" + json2);
显示结果
1 ——用JSONSerializer将string转换json——{"1":1} 2 ——用JSONSerializer将string转换jsonArray——[1,1]
将java数组和集合转换成json
1 // Working with arrays and collections,——>json 2 boolean[] booleanArray = new boolean[] { true, false, true }; 3 JSONArray fromObject = JSONArray.fromObject(booleanArray); 4 System.out.println(fromObject); 5 6 List list = new ArrayList(); 7 list.add("first"); 8 list.add("second"); 9 JSONArray fromObject2 = JSONArray.fromObject(list); 10 System.out.println(fromObject2);
结果
1 [true,false,true] 2 ["first","second"]
将beans和map转换成json
1 // Working with objects 2 // From Beans & Maps toJSON 3 Map map = new HashMap(); 4 map.put("name", "json"); 5 map.put("bool", Boolean.TRUE); 6 map.put("int", new Integer(1)); 7 map.put("arr", new String[] { "a", "b" }); 8 map.put("func", "function(i){ return this.arr[i]; }"); 9 10 JSONObject jsonObject2 = JSONObject.fromObject(map); 11 System.out.println("——map转换json——\n" + jsonObject2);
结果
1 ——map转换json—— 2 {"arr":["a","b"],"int":1,"name":"json","func":function(i){ return this.arr[i]; },"bool":true}
beans转换先自定义对象Mybean,
1 public class MyBean { 2 3 private String name = "json"; 4 private int pojoId = 1; 5 private char[] options = new char[] { ‘a‘, ‘f‘ }; 6 private String func1 = "function(i){ return this.options[i]; }"; 7 private JSONFunction func2 = new JSONFunction(new String[] { "i" }, 8 "return this.options[i];"); 9 //自定义类型 10 private MyBean2 mybean2 = new MyBean2("1", "mybean"); 11 12 public String getName() { 13 return name; 14 } 15 public void setName(String name) { 16 this.name = name; 17 } 18 public int getPojoId() { 19 return pojoId; 20 } 21 public void setPojoId(int pojoId) { 22 this.pojoId = pojoId; 23 } 24 public char[] getOptions() { 25 return options; 26 } 27 public void setOptions(char[] options) { 28 this.options = options; 29 } 30 public String getFunc1() { 31 return func1; 32 } 33 public void setFunc1(String func1) { 34 this.func1 = func1; 35 } 36 public JSONFunction getFunc2() { 37 return func2; 38 } 39 public void setFunc2(JSONFunction func2) { 40 this.func2 = func2; 41 } 42 public MyBean2 getMybean2() { 43 return mybean2; 44 } 45 public void setMybean2(MyBean2 mybean2) { 46 this.mybean2 = mybean2; 47 } 48 }
Mybean中包含自定义对象Mybean2
public class MyBean2 { private String id; private String name; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public MyBean2(String id, String name) { super(); this.id = id; this.name = name; } public MyBean2() { super(); } }
将beans转换为json
1 // 自定义MyBean对象中包含MyBean2对象,所以bean——>Json,无论是否自定义对象,都可以转换json格式 2 JSONObject jsonObject3 = JSONObject.fromObject(new MyBean()); 3 System.out.println("——beans转换json——\n" + jsonObject3);
结果
1 ——beans转换json—— 2 {"name":"json","mybean2":{"id":"1","name":"mybean"},"pojoId":1,"func1":function(i){ return this.options[i]; },"func2":function(i){ return this.options[i]; },"options":["a","f"]}
总结:将java对象转换成json,比较简单,若是beans或maps用JSONObject.fromObject() ,若是array或collections,用JSONArray.fromObject()。
时间: 2024-10-13 17:21:18