json的java资源and sample

Example 1-1 - Encode a JSON object //import org.json.simple.JSONObject; JSONObject obj=new JSONObject(); obj.put("name","foo"); obj.put("num",new Integer(100)); obj.put("balance",new Double(1000.21)); obj.put("is_vip",new Boolean(true)); obj.put("nickname",null); System.out.print(obj); Result: {"balance":1000.21,"num":100,"nickname":null,"is_vip":true,"name":"foo"} JSONObject is subclass of java.util.HashMap. No ordering is provided. If you need strict ordering of elements use JSONValue.toJSONString( map ) method with ordered map implementation such as java.util.LinkedHashMap (see example 1-3). Example 1-2 - Encode a JSON object - Streaming //import org.json.simple.JSONObject; JSONObject obj=new JSONObject(); obj.put("name","foo"); obj.put("num",new Integer(100)); obj.put("balance",new Double(1000.21)); obj.put("is_vip",new Boolean(true)); obj.put("nickname",null); StringWriter out = new StringWriter(); obj.writeJSONString(out); String jsonText = out.toString(); System.out.print(jsonText); Result: {"balance":1000.21,"num":100,"nickname":null,"is_vip":true,"name":"foo"} JSONObject is subclass of java.util.HashMap. No ordering is provided. If you need strict ordering of elements use JSONValue.toJSONString( map ) method with ordered map implementation such as java.util.LinkedHashMap (see example 1-3). Example 1-3 - Encode a JSON object - Using Map //import java.util.LinkedHashMap; //import java.util.Map; //import org.json.simple.JSONValue; Map obj=new LinkedHashMap(); obj.put("name","foo"); obj.put("num",new Integer(100)); obj.put("balance",new Double(1000.21)); obj.put("is_vip",new Boolean(true)); obj.put("nickname",null); String jsonText = JSONValue.toJSONString(obj); System.out.print(jsonText); Result: {"name":"foo","num":100,"balance":1000.21,"is_vip":true,"nickname":null} Now the order of the object entries is preserved, which is different from example 1-1. Example 1-4 - Encode a JSON object - Using Map and streaming //import java.util.LinkedHashMap; //import java.util.Map; //import org.json.simple.JSONValue; Map obj=new LinkedHashMap(); obj.put("name","foo"); obj.put("num",new Integer(100)); obj.put("balance",new Double(1000.21)); obj.put("is_vip",new Boolean(true)); obj.put("nickname",null); StringWriter out = new StringWriter(); JSONValue.writeJSONString(obj, out); String jsonText = out.toString(); System.out.print(jsonText); Result: {"name":"foo","num":100,"balance":1000.21,"is_vip":true,"nickname":null} Example 2-1 - Encode a JSON array //import org.json.simple.JSONArray; JSONArray list = new JSONArray(); list.add("foo"); list.add(new Integer(100)); list.add(new Double(1000.21)); list.add(new Boolean(true)); list.add(null); System.out.print(list); Result: ["foo",100,1000.21,true,null] Example 2-2 - Encode a JSON array - Streaming //import org.json.simple.JSONArray; JSONArray list = new JSONArray(); list.add("foo"); list.add(new Integer(100)); list.add(new Double(1000.21)); list.add(new Boolean(true)); list.add(null); StringWriter out = new StringWriter(); list.writeJSONString(out); String jsonText = out.toString(); System.out.print(jsonText); Result: ["foo",100,1000.21,true,null] Example 2-3 - Encode a JSON array - Using List //import org.json.simple.JSONValue; LinkedList list = new LinkedList(); list.add("foo"); list.add(new Integer(100)); list.add(new Double(1000.21)); list.add(new Boolean(true)); list.add(null); String jsonText = JSONValue.toJSONString(list); System.out.print(jsonText); Result: ["foo",100,1000.21,true,null] Example 2-4 - Encode a JSON array - Using List and streaming //import org.json.simple.JSONValue; LinkedList list = new LinkedList(); list.add("foo"); list.add(new Integer(100)); list.add(new Double(1000.21)); list.add(new Boolean(true)); list.add(null); StringWriter out = new StringWriter(); JSONValue.writeJSONString(list, out); String jsonText = out.toString(); System.out.print(jsonText); Result: ["foo",100,1000.21,true,null] Example 3 - Merge two JSON objects //import org.json.simple.JSONObject; JSONObject obj1 = new JSONObject(); obj1.put("name","foo"); obj1.put("num",new Integer(100)); obj1.put("balance",new Double(1000.21)); JSONObject obj2 = new JSONObject(); obj2.put("is_vip",new Boolean(true)); obj2.put("nickname",null); obj2.putAll(obj1); System.out.print(obj2); Result: {"balance":1000.21,"num":100,"nickname":null,"is_vip":true,"name":"foo"}, the same as the one of Example 1. Example 4 - Merge two JSON arrays JSONArray list1 = new JSONArray(); list1.add("foo"); list1.add(new Integer(100)); list1.add(new Double(1000.21)); JSONArray list2 = new JSONArray(); list2.add(new Boolean(true)); list2.add(null); list2.addAll(list1); System.out.print(list2); Result: [true,null,"foo",100,1000.21], the order of which is different from the one of Example 2. Example 5-1 - Combination of JSON primitives, JSON object and JSON arrays JSONArray list1 = new JSONArray(); list1.add("foo"); list1.add(new Integer(100)); list1.add(new Double(1000.21)); JSONArray list2 = new JSONArray(); list2.add(new Boolean(true)); list2.add(null); JSONObject obj = new JSONObject(); obj.put("name","foo"); obj.put("num",new Integer(100)); obj.put("balance",new Double(1000.21)); obj.put("is_vip",new Boolean(true)); obj.put("nickname",null); obj.put("list1", list1); obj.put("list2", list2); System.out.println(obj); Result: {"balance":1000.21,"list2":[true,null],"num":100,"list1":["foo",100,1000.21],"nickname":null,"is_vip":true,"name":"foo"} Example 5-2 - Combination of JSON primitives, Map and List Map m1 = new LinkedHashMap(); Map m2 = new HashMap(); List l1 = new LinkedList(); m1.put("k11","v11"); m1.put("k12","v12"); m1.put("k13", "v13"); m2.put("k21","v21"); m2.put("k22","v22"); m2.put("k23","v23"); l1.add(m1); l1.add(m2); String jsonString = JSONValue.toJSONString(l1); System.out.println(jsonString); Result: [{"k11":"v11","k12":"v12","k13":"v13"},{"k22":"v22","k21":"v21","k23":"v23"}] Example 5-3 - Combination of JSON primitives, JSONObject, Map and List, and streaming StringWriter out = new StringWriter(); JSONObject obj = new JSONObject(); LinkedHashMap m1 = new LinkedHashMap(); LinkedList l1 = new LinkedList(); obj.put("k1", "v1"); obj.put("k2", m1); obj.put("k3", l1); m1.put("mk1", "mv1"); l1.add("lv1"); l1.add("lv2"); m1.put("mk2", l1); obj.writeJSONString(out); System.out.println("jsonString:"); System.out.println(out.toString()); String jsonString = obj.toJSONString(); System.out.println(jsonString); Result: jsonString: {"k3":["lv1","lv2"],"k1":"v1","k2":{"mk1":"mv1","mk2":["lv1","lv2"]}} {"k3":["lv1","lv2"],"k1":"v1","k2":{"mk1":"mv1","mk2":["lv1","lv2"]}} Example 6-1 - Customize JSON outputs /*class User implements JSONAware{ private int id; private String name; private String password; public User(int id, String name, String password){ this.id = id; this.name = name; this.password = password; } public String toJSONString(){ StringBuffer sb = new StringBuffer(); sb.append("{"); sb.append(JSONObject.esca