标签：
http://www.cnblogs.com/henryxu/archive/2013/03/10/2952738.html
JSON jar包：
1 /** 2 * 从json数组中得到相应java数组 3 * JSONArray下的toArray()方法的使用 4 * @param str 5 * @return 6 */ 7 public static Object[] getJsonToArray(String str) { 8 JSONArray jsonArray = JSONArray.fromObject(str); 9 return jsonArray.toArray(); 10 } 11 12 public static void main(String[] args) { 13 JSONArray jsonStrs = new JSONArray(); 14 jsonStrs.add(0, "cat"); 15 jsonStrs.add(1, "dog"); 16 jsonStrs.add(2, "bird"); 17 jsonStrs.add(3, "duck"); 18 19 Object[] obj=getJsonToArray(jsonStrs.toString()); 20 for(int i=0;i<obj.length;i++){ 21 System.out.println(obj[i]); 22 } 23 }
1 package jsontest; 2 3 import net.sf.json.JSONArray; 4 import net.sf.json.JSONObject; 5 6 public class JSONObjectSample { 7 8 // 创建JSONObject对象 9 private static JSONObject createJSONObject() { 10 JSONObject jsonObject = new JSONObject(); 11 jsonObject.put("username", "huangwuyi"); 12 jsonObject.put("sex", "男"); 13 jsonObject.put("QQ", "413425430"); 14 jsonObject.put("Min.score", new Integer(99)); 15 jsonObject.put("nickname", "梦中心境"); 16 return jsonObject; 17 } 18 19 public static void main(String[] args) { 20 JSONObject jsonObject = JSONObjectSample.createJSONObject();//静待方法，直接通过类名+方法调用 21 // 输出jsonobject对象 22 System.out.println("jsonObject：" + jsonObject); 23 24 // 判读输出对象的类型 25 boolean isArray = jsonObject.isArray(); 26 boolean isEmpty = jsonObject.isEmpty(); 27 boolean isNullObject = jsonObject.isNullObject(); 28 System.out.println("是否为数组:" + isArray + "， 是否为空:" + isEmpty 29 + "， isNullObject:" + isNullObject); 30 31 // 添加属性，在jsonObject后面追加元素。 32 jsonObject.element("address", "福建省厦门市"); 33 System.out.println("添加属性后的对象：" + jsonObject); 34 35 // 返回一个JSONArray对象 36 JSONArray jsonArray = new JSONArray(); 37 jsonArray.add(0, "this is a jsonArray value"); 38 jsonArray.add(1, "another jsonArray value"); 39 jsonObject.element("jsonArray", jsonArray); 40 //在jsonObject后面追加一个jsonArray 41 JSONArray array = jsonObject.getJSONArray("jsonArray"); 42 System.out.println(jsonObject); 43 44 45 System.out.println("返回一个JSONArray对象：" + array); 46 // 添加JSONArray后的值 47 // {"username":"huangwuyi","sex":"男","QQ":"413425430","Min.score":99,"nickname":"梦中心境","address":"福建省厦门市","jsonArray":["this is a jsonArray value","another jsonArray value"]} 48 System.out.println("结果=" + jsonObject); 49 50 // 根据key返回一个字符串 51 String username = jsonObject.getString("username"); 52 System.out.println("username==>" + username); 53 54 // 把字符转换为 JSONObject 55 String temp = jsonObject.toString(); 56 JSONObject object = JSONObject.fromObject(temp); 57 // 转换后根据Key返回值 58 System.out.println("qq=" + object.get("QQ")); 59 60 } 61 62 }
在网页中想后台传递多个数据时，有时数据还是多个动态列表，数据很复杂时，JavaScript程序员喜欢把他们作为json串进行处理，后台收到后需要对json字符串进行解析，幸好有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/
1 public class Test { 2 3 /** 4 5 * @param args 6 7 * @author wen 8 9 */ 10 11 public static void main(String[] args) { 12 13 // test1(); 14 15 // test2(); 16 17 String json = “{1:{1:{jhinfo:[‘计划一‘,‘亲亲宝宝‘,‘www.wenhq.com‘],jhrate:[‘1-5:10.0‘,‘6-100:5.0/1‘]},2:{jhinfo:[‘计划二‘,‘亲亲宝宝‘,‘www.wenhq.com‘],jhrate:[‘1-100:100.0‘]},3:{jhinfo:[‘计划三‘,‘亲亲宝宝‘,‘www.wenhq.com‘],jhrate:[‘1-100:150.0/7‘]}},2:{4:{jhinfo:[‘年计划‘,‘亲亲宝宝‘,‘www.wenhq.com‘],jhrate:[‘365-365:1000.0‘]}}}”; 18 19 try { 20 21 JSONObject jsonObject = JSONObject.fromObject(json); 22 23 String name = jsonObject.getString(“1″); 24 25 String address = jsonObject.getString(“2″); 26 27 System.out.println(“name is:” + name); 28 29 System.out.println(“address is:” + address); 30 31 Iterator it=jsonObject.keys(); 32 33 while (it.hasNext()){ 34 35 System.out.println(jsonObject.get(it.next())); 36 37 } 38 39 } catch (JSONException e) { 40 41 e.printStackTrace(); 42 43 } 44 45 } 46 47 /** 48 49 * json对象字符串转换 50 51 * @author wen 52 53 */ 54 55 private static void test2() { 56 57 String json = “{‘name’: ‘亲亲宝宝’,‘array’:[{‘a‘:‘111‘,‘b‘:‘222‘,‘c‘:‘333‘},{},{‘a‘:‘999‘}],’address’:‘亲亲宝宝’}”; 58 59 try { 60 61 JSONObject jsonObject = JSONObject.fromObject(json); 62 63 String name = jsonObject.getString(“name”); 64 65 String address = jsonObject.getString(“address”); 66 67 System.out.println(“name is:” + name); 68 69 System.out.println(“address is:” + address); 70 71 JSONArray jsonArray = jsonObject.getJSONArray(“array”); 72 73 for (int i = 0; i < jsonArray.size(); i++) { 74 75 System.out.println(“item ” + i + ” :” + jsonArray.getString(i)); 76 77 } 78 79 } catch (JSONException e) { 80 81 e.printStackTrace(); 82 83 } 84 85 } 86 87 /** 88 89 * json数组 转换，数组以[开头 90 91 * @author wen 92 93 */ 94 95 private static void test1() { 96 97 boolean[] boolArray = new boolean[]{true,false,true}; 98 99 JSONArray jsonArray1 = JSONArray.fromObject( boolArray ); 100 101 System.out.println( jsonArray1 ); 102 103 // prints [true,false,true] 104 105 List list = new ArrayList(); 106 107 list.add( “first” ); 108 109 list.add( “second” ); 110 111 JSONArray jsonArray2 = JSONArray.fromObject( list ); 112 113 System.out.println( jsonArray2 ); 114 115 // prints ["first","second"] 116 117 JSONArray jsonArray3 = JSONArray.fromObject( “[‘json‘,‘is‘,‘easy‘]” ); 118 119 System.out.println( jsonArray3 ); 120 121 // prints ["json","is","easy"] 122 123 }
创建JSONArray的常用四种方法
1.从头或者从零开始，创建一个JSONArray(Creating a JSONArray from scratch)
实例1：
Java代码
JSONArray jsonArray = new JSONArray().element("JSON").element("1").element("2.0").element("true");
assertEquals("JSON", jsonArray.getString(0));
assertEquals(1, jsonArray.getInt(1));
assertEquals(2.0d, jsonArray.getDouble(2), 0d);
assertTrue(jsonArray.getBoolean(3));
3.使用一个Collection来创建一个JSONArray(Creating a JSONArray from a Collection)
实例1：
Java代码
List list = new ArrayList();
list.add( "JSON" );
list.add( "1" );
list.add( "2.0" );
list.add( "true" );
JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON( list ); assertEquals( "JSON", jsonArray.getString(0) );
assertEquals( 1, jsonArray.getInt(1) );
assertEquals( 2.0d, jsonArray.getDouble(2), 0d );
assertTrue( jsonArray.getBoolean(3) );
4.使用一个Array来创建一个JSONArray(Creating a JSONArray from an array)
实例1：
Java代码
Object[] array = new Object[] { "JSON", 1, 2.0, true };
JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON(array); assertEquals("JSON", jsonArray.getString(0));
assertEquals(1, jsonArray.getInt(1));
assertEquals(2.0d, jsonArray.getDouble(2), 0d);
assertTrue(jsonArray.getBoolean(3));
//实例2：
Object[] array = new Object[] { "JSON", 1, 2.0, true };
JSONArray jsonArray = JSONArray.fromObject(array);
assertEquals("JSON", jsonArray.getString(0));
assertEquals(1, jsonArray.getInt(1));
assertEquals(2.0d, jsonArray.getDouble(2), 0d);
assertTrue(jsonArray.getBoolean(3));
由此可见，无论要转换的源是哪种类型，都可以使用(JSONArray) JSONSerializer.toJSON()或JSONArray.fromObject()来转换;
常用的三种扩展功能
1.使用一个JSON格式化字符串来创建一个JSONFunction(JavaScript functions)
实例：
Java代码
String str = "{func: function( param ){ doSomethingWithParam(param); }}";
JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(str); JSONFunction func = (JSONFunction) jsonObject.get("func"); ArrayAssertions.assertEquals(new String[] { "param" }, func.getParams());
assertEquals("doSomethingWithParam(param);", func.getText());
注：函数的写法要注意function(){},参数param是可选的！
2.排除一个JSON格式化字符串的某些属性(Exclude properties)
实例：
Java代码
String str = "{‘string‘:‘JSON‘, ‘integer‘: 1, ‘double‘: 2.0, ‘boolean‘: true}";
JsonConfig jsonConfig = new JsonConfig();
jsonConfig.setExcludes(new String[] { "double", "boolean" }); JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(str, jsonConfig);
assertEquals("JSON", jsonObject.getString("string"));
assertEquals(1, jsonObject.getInt("integer"));
assertFalse(jsonObject.has("double"));
assertFalse(jsonObject.has("boolean"));
3.排除一个JSON格式化字符串的某些属性,使用过滤器(Exclude properties (with filters)
实例：
Java代码
String str = "{‘string‘:‘JSON‘, ‘integer‘: 1, ‘double‘: 2.0, ‘boolean‘: true}";
JsonConfig jsonConfig = new JsonConfig(); jsonConfig.setJsonPropertyFilter(new PropertyFilter() {
public boolean apply(Object source, String name, Object value) {
if ("double".equals(name) || "boolean".equals(name))
{ return true; }
return false; } });
JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(str, jsonConfig);
assertEquals("JSON", jsonObject.getString("string"));
assertEquals(1, jsonObject.getInt("integer"));
assertFalse(jsonObject.has("double"));
assertFalse(jsonObject.has("boolean"));
JSONObject-Java常用的四种用法
1.JSONObject to DynaBean
Java代码
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"));
2.JSONObject to JavaBean
Java代码
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);
3.JSONArray to List
Java代码
String json = "[\"first\",\"second\"]";
JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON(json);
List output = (List) JSONSerializer.toJava(jsonArray);
4.JSONArray to array
Java代码
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);
理论上，这样就可以了，但时，有异常Caused by: java.lang.NoSuchMethodException: com.json.Json$UserBean.<init>()
2.使用一个JSON格式化字符串来创建一个JSONArray(Creating a JSONArray from a JSON formatted string)
实例1：
Java代码
String str = "[‘JSON‘, 1, 2.0, true]"; //注意该字符串的格式"[ , ]" JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON( str ); assertEquals( "JSON", jsonArray.getString(0) );
assertEquals( 1, jsonArray.getInt(1) );
assertEquals( 2.0d, jsonArray.getDouble(2), 0d );
assertTrue( jsonArray.getBoolean(3) );
Java代码
List<String> list = new ArryList<String>(); list.add("a"); list.add("b"); Map<String,List<String>> map = new HashMap<String,List<String>>(); map.put("list",list); MessageUtils.outputJSONResult(JSONObject.fromObject(map).toString(), response); public class MessageUtils { public static void outputJSONResult(String result, HttpServletResponse response) { try { response.setHeader("ContentType", "text/json"); response.setCharacterEncoding("utf-8"); PrintWriter pw = response.getWriter(); pw.write(result); pw.flush(); pw.close(); } catch (IOException e) { e.printStackTrace(); } }
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原文地址：http://www.cnblogs.com/yg6405816/p/5798889.html
