JSON-lib框架，转换JSON、XML不再困难（转）
Json-lib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对象或是将xml字符串转换成Java对象。
一、 准备工作
1、 首先要去官方下载json-lib工具包
下载地址：
http://sourceforge.net/projects/json-lib/files/json-lib/json-lib-2.4/
目前最新的是2.4的版本，本示例中使用的是v2.3；json-lib还需要以下依赖包：
jakarta commons-lang 2.5
jakarta commons-beanutils 1.8.0
jakarta commons-collections 3.2.1
jakarta commons-logging 1.1.1
ezmorph 1.0.6
官方网址：http://json-lib.sourceforge.net/
然后在工程中添加如下jar包：
当然你也可以用2.4的json-lib库
你可以在这里看看官方提供的示例：
http://json-lib.sourceforge.net/usage.html
由于本次介绍的示例需要junit工具，所以你还需要添加junit的jar文件，版本是4.8.2版本的，下载地址：https://github.com/KentBeck/junit/downloads
如果你还不了解JSON是什么？那么你应该可以看看http://www.json.org/json-zh.html
2、 要转换的JavaBean的代码如下：
package com.hoo.entity; public class Student { private int id; private String name; private String email; private String address; private Birthday birthday; //setter、getter public String toString() { return this.name + "#" + this.id + "#" + this.address + "#" + this.birthday + "#" + this.email; }} Birthday.javapackage com.hoo.entity; public class Birthday { private String birthday; public Birthday(String birthday) { super(); this.birthday = birthday; } //setter、getter public Birthday() {} @Override public String toString() { return this.birthday; }}package com.hoo.test; import java.lang.reflect.InvocationTargetException;import java.util.ArrayList;import java.util.Collection;import java.util.Date;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Set;import net.sf.json.JSON;import net.sf.json.JSONArray;import net.sf.json.JSONFunction;import net.sf.json.JSONObject;import net.sf.json.JSONSerializer;import net.sf.json.JsonConfig;import net.sf.json.processors.JsonValueProcessor;import net.sf.json.util.PropertyFilter;import net.sf.json.xml.XMLSerializer;import org.apache.commons.beanutils.PropertyUtils;import org.junit.After;import org.junit.Before;import org.junit.Test;import com.hoo.entity.Birthday;import com.hoo.entity.Student; /** * <b>function:</b> 用json-lib转换java对象到JSON字符串 * 读取json字符串到java对象，序列化jsonObject到xml * json-lib-version: json-lib-2.3-jdk15.jar * 依赖包: * commons-beanutils.jar * commons-collections-3.2.jar * ezmorph-1.0.3.jar * commons-lang.jar * commons-logging.jar * @author hoojo * @createDate Nov 28, 2010 2:28:39 PM * @file JsonlibTest.java * @package com.hoo.test * @project WebHttpUtils * @blog http://blog.csdn.net/IBM_hoojo * @email hoojo_@126.com * @version 1.0 */@SuppressWarnings({ "deprecation", "unchecked" })public class JsonlibTest { private JSONArray jsonArray = null; private JSONObject jsonObject = null; private Student bean = null; @Before public void init() { jsonArray = new JSONArray(); jsonObject = new JSONObject(); bean = new Student(); bean.setAddress("address"); bean.setEmail("email"); bean.setId(1); bean.setName("haha"); Birthday day = new Birthday(); day.setBirthday("2010-11-22"); bean.setBirthday(day); } @After public void destory() { jsonArray = null; jsonObject = null; bean = null; System.gc(); } public final void fail(String string) { System.out.println(string); } public final void failRed(String string) { System.err.println(string); } }/*=========================Java Object >>>> JSON String ===========================*//** * <b>function:</b>转Java Bean对象到JSON * @author hoojo * @createDate Nov 28, 2010 2:35:54 PM */@Testpublic void writeEntity2JSON() { fail("==============Java Bean >>> JSON Object=================="); fail(JSONObject.fromObject(bean).toString()); fail("==============Java Bean >>> JSON Array=================="); fail(JSONArray.fromObject(bean).toString());//array会在最外层套上[] fail("==============Java Bean >>> JSON Object =================="); fail(JSONSerializer.toJSON(bean).toString()); fail("========================JsonConfig========================"); JsonConfig jsonConfig = new JsonConfig(); jsonConfig.registerJsonValueProcessor(Birthday.class, new JsonValueProcessor() { public Object processArrayValue(Object value, JsonConfig jsonConfig) { if (value == null) { return new Date(); } return value; } public Object processObjectValue(String key, Object value, JsonConfig jsonConfig) { fail("key:" + key); return value + "##修改过的日期"; } }); jsonObject = JSONObject.fromObject(bean, jsonConfig); fail(jsonObject.toString()); Student student = (Student) JSONObject.toBean(jsonObject, Student.class); fail(jsonObject.getString("birthday")); fail(student.toString()); fail("#####################JsonPropertyFilter############################"); jsonConfig.setJsonPropertyFilter(new PropertyFilter() { public boolean apply(Object source, String name, Object value) { fail(source + "%%%" + name + "--" + value); //忽略birthday属性 if (value != null && Birthday.class.isAssignableFrom(value.getClass())) { return true; } return false; } }); fail(JSONObject.fromObject(bean, jsonConfig).toString()); fail("#################JavaPropertyFilter##################"); jsonConfig.setRootClass(Student.class); jsonConfig.setJavaPropertyFilter(new PropertyFilter() { public boolean apply(Object source, String name, Object value) { fail(name + "@" + value + "#" + source); if ("id".equals(name) || "email".equals(name)) { value = name + "@@"; return true; } return false; } }); //jsonObject = JSONObject.fromObject(bean, jsonConfig); //student = (Student) JSONObject.toBean(jsonObject, Student.class); //fail(student.toString()); student = (Student) JSONObject.toBean(jsonObject, jsonConfig); fail("Student:" + student.toString());}/** * <b>function:</b>转换Java List集合到JSON * @author hoojo * @createDate Nov 28, 2010 2:36:15 PM */@Testpublic void writeList2JSON() { fail("==============Java List >>> JSON Array=================="); List<Student> stu = new ArrayList<Student>(); stu.add(bean); bean.setName("jack"); stu.add(bean); fail(JSONArray.fromObject(stu).toString()); fail(JSONSerializer.toJSON(stu).toString());}/** * <b>function:</b>转Java Map对象到JSON * @author hoojo * @createDate Nov 28, 2010 2:37:35 PM */@Testpublic void writeMap2JSON() { Map<String, Object> map = new HashMap<String, Object>(); map.put("A", bean); bean.setName("jack"); map.put("B", bean); 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]; }"); fail("==============Java Map >>> JSON Object=================="); fail(JSONObject.fromObject(map).toString()); fail("==============Java Map >>> JSON Array =================="); fail(JSONArray.fromObject(map).toString()); fail("==============Java Map >>> JSON Object=================="); fail(JSONSerializer.toJSON(map).toString());}/** * <b>function:</b> 转换更多数组类型到JSON * @author hoojo * @createDate Nov 28, 2010 2:39:19 PM */@Testpublic void writeObject2JSON() { String[] sa = {"a", "b", "c"}; fail("==============Java StringArray >>> JSON Array =================="); fail(JSONArray.fromObject(sa).toString()); fail(JSONSerializer.toJSON(sa).toString()); fail("==============Java boolean Array >>> JSON Array =================="); boolean[] bo = { true, false, true }; fail(JSONArray.fromObject(bo).toString()); fail(JSONSerializer.toJSON(bo).toString()); Object[] o = { 1, "a", true, 'A', sa, bo }; fail("==============Java Object Array >>> JSON Array =================="); fail(JSONArray.fromObject(o).toString()); fail(JSONSerializer.toJSON(o).toString()); fail("==============Java String >>> JSON =================="); fail(JSONArray.fromObject("['json','is','easy']").toString()); fail(JSONObject.fromObject("{'json':'is easy'}").toString()); fail(JSONSerializer.toJSON("['json','is','easy']").toString()); fail("==============Java JSONObject >>> JSON =================="); jsonObject = new JSONObject() .element("string", "JSON") .element("integer", "1") .element("double", "2.0") .element("boolean", "true"); fail(JSONSerializer.toJSON(jsonObject).toString()); fail("==============Java JSONArray >>> JSON =================="); jsonArray = new JSONArray() .element( "JSON" ) .element( "1" ) .element( "2.0" ) .element( "true" ); fail(JSONSerializer.toJSON(jsonArray).toString()); fail("==============Java JSONArray JsonConfig#setArrayMode >>> JSON =================="); List input = new ArrayList(); input.add("JSON"); input.add("1"); input.add("2.0"); input.add("true"); JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON( input ); JsonConfig jsonConfig = new JsonConfig(); jsonConfig.setArrayMode( JsonConfig.MODE_OBJECT_ARRAY ); Object[] output = (Object[]) JSONSerializer.toJava(jsonArray, jsonConfig); System.out.println(output[0]); fail("==============Java JSONFunction >>> JSON =================="); String str = "{'func': function( param ){ doSomethingWithParam(param); }}"; JSONObject jsonObject = (JSONObject) JSONSerializer.toJSON(str); JSONFunction func = (JSONFunction) jsonObject.get("func"); fail(func.getParams()[0]); fail(func.getText() ); }private String json = "{"address":"chian","birthday":{"birthday":"2010-11-22"}," + ""email":"email@123.com","id":22,"name":"tom"}";/** * <b>function:</b>将json字符串转化为java对象 * @author hoojo * @createDate Nov 28, 2010 3:01:16 PM */@Testpublic void readJSON2Bean() { fail("==============JSON Object String >>> Java Bean =================="); jsonObject = JSONObject.fromObject(json); Student stu = (Student) JSONObject.toBean(jsonObject, Student.class); fail(stu.toString());}private String json = "{"address":"chian","birthday":{"birthday":"2010-11-22"},"+ ""email":"email@123.com","id":22,"name":"tom"}"; @Testpublic void readJSON2DynaBean() { try { fail("==============JSON Object String >>> Java MorphDynaBean =================="); JSON jo = JSONSerializer.toJSON(json); Object o = JSONSerializer.toJava(jo);//MorphDynaBean fail(PropertyUtils.getProperty(o, "address").toString()); jsonObject = JSONObject.fromObject(json); fail(jsonObject.getString("email")); o = JSONSerializer.toJava(jsonObject);//MorphDynaBean fail(PropertyUtils.getProperty(o, "name").toString()); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } catch (NoSuchMethodException e) { e.printStackTrace(); }}private String json = "{"address":"chian","birthday":{"birthday":"2010-11-22"},"+ ""email":"email@123.com","id":22,"name":"tom"}"; @Testpublic void readJSON2Array() { try { fail("==============JSON Arry String >>> Java Array =================="); json = "[" + json + "]"; jsonArray = JSONArray.fromObject(json); fail("#%%%" + jsonArray.get(0).toString()); Object[] os = jsonArray.toArray(); System.out.println(os.length); fail(JSONArray.fromObject(json).join("")); fail(os[0].toString()); Student[] stus = (Student[]) JSONArray.toArray(jsonArray, Student.class); System.out.println(stus.length); System.out.println(stus[0]); } catch (Exception e) { e.printStackTrace(); }}private String json = "{"address":"chian","birthday":{"birthday":"2010-11-22"},"+ ""email":"email@123.com","id":22,"name":"tom"}"; @Testpublic void readJSON2List() { try { fail("==============JSON Arry String >>> Java List =================="); json = "[" + json + "]"; jsonArray = JSONArray.fromObject(json); List<Student> list = JSONArray.toList(jsonArray, Student.class); System.out.println(list.size()); System.out.println(list.get(0)); list = JSONArray.toList(jsonArray); System.out.println(list.size()); System.out.println(list.get(0));//MorphDynaBean } catch (Exception e) { e.printStackTrace(); }}private String json = "{"address":"chian","birthday":{"birthday":"2010-11-22"},"+ ""email":"email@123.com","id":22,"name":"tom"}"; @Testpublic void readJSON2Collection() { try { fail("==============JSON Arry String >>> Java Collection =================="); json = "[" + json + "]"; jsonArray = JSONArray.fromObject(json); Collection<Student> con = JSONArray.toCollection(jsonArray, Student.class); System.out.println(con.size()); Object[] stt = con.toArray(); System.out.println(stt.length); fail(stt[0].toString()); } catch (Exception e) { e.printStackTrace(); }}@Testpublic void readJSON2Map() { try { fail("==============JSON Arry String >>> Java Map =================="); json = "{"arr":["a","b"],"A":{"address":"address","birthday":{"birthday":"2010-11-22"},"+ ""email":"email","id":1,"name":"jack"},"int":1,"+ ""B":{"address":"address","birthday":{"birthday":"2010-11-22"},"+ ""email":"email","id":1,"name":"jack"},"name":"json","bool":true}"; jsonObject = JSONObject.fromObject(json); Map<String, Class<?>> clazzMap = new HashMap<String, Class<?>>(); clazzMap.put("arr", String[].class); clazzMap.put("A", Student.class); clazzMap.put("B", Student.class); Map<String, ?> mapBean = (Map) JSONObject.toBean(jsonObject, Map.class, clazzMap); System.out.println(mapBean); Set<String> set = mapBean.keySet(); Iterator<String> iter = set.iterator(); while (iter.hasNext()) { String key = iter.next(); fail(key + ":" + mapBean.get(key).toString()); } } catch (Exception e) { e.printStackTrace(); }}/*============================Java Object >>>>> XML ==========================*//** * <b>function:</b> 转换Java对象到XML * 需要额外的jar包：xom.jar * @author hoojo * @createDate Nov 28, 2010 2:39:55 PM */@Testpublic void writeObject2XML() { XMLSerializer xmlSerializer = new XMLSerializer(); fail("==============Java String Array >>> XML =================="); //xmlSerializer.setElementName("bean"); fail(xmlSerializer.write(JSONArray.fromObject(bean))); String[] sa = {"a", "b", "c"}; fail("==============Java String Array >>> XML =================="); fail(xmlSerializer.write(JSONArray.fromObject(sa))); fail("==============Java boolean Array >>> XML =================="); boolean[] bo = { true, false, true }; fail(xmlSerializer.write(JSONArray.fromObject(bo))); fail(xmlSerializer.write(JSONSerializer.toJSON(bo))); Object[] o = { 1, "a", true, 'A', sa, bo }; fail("==============Java Object Array >>> JSON Array =================="); fail(xmlSerializer.write(JSONArray.fromObject(o))); fail(xmlSerializer.write(JSONSerializer.toJSON(o))); fail("==============Java String >>> JSON =================="); fail(xmlSerializer.write(JSONArray.fromObject("['json','is','easy']")).toString()); fail(xmlSerializer.write(JSONObject.fromObject("{'json':'is easy'}")).toString()); fail(xmlSerializer.write(JSONSerializer.toJSON("['json','is','easy']")).toString());}/*============================XML String >>>>> Java Object ==========================*//** * <b>function:</b>转换xml文档到java对象 * @author hoojo * @createDate Nov 28, 2010 3:00:27 PM */@Testpublic void readXML2Object() { XMLSerializer xmlSerializer = new XMLSerializer(); fail("============== XML >>>> Java String Array =================="); String[] sa = {"a", "b", "c"}; jsonArray = (JSONArray) xmlSerializer.read(xmlSerializer.write(JSONArray.fromObject(sa))); fail(jsonArray.toString()); String[] s = (String[]) JSONArray.toArray(jsonArray, String.class); fail(s[0].toString()); fail("============== XML >>>> Java boolean Array =================="); boolean[] bo = { true, false, true }; jsonArray = (JSONArray) xmlSerializer.read(xmlSerializer.write(JSONArray.fromObject(bo))); bo = (boolean[]) JSONArray.toArray(jsonArray, boolean.class); fail(bo.toString()); System.out.println(bo[0]); jsonArray = (JSONArray) xmlSerializer.read(xmlSerializer.write(JSONSerializer.toJSON(bo))); bo = (boolean[]) JSONArray.toArray(jsonArray, boolean.class); fail(bo.toString()); System.out.println(bo[0]); fail("==============Java Object Array >>> JSON Array =================="); Object[] o = { 1, "a", true, 'A', sa, bo }; jsonArray = (JSONArray) xmlSerializer.read(xmlSerializer.write(JSONArray.fromObject(o))); System.out.println(jsonArray.getInt(0)); System.out.println(jsonArray.get(1)); System.out.println(jsonArray.getBoolean(2)); jsonArray = (JSONArray) xmlSerializer.read(xmlSerializer.write(JSONSerializer.toJSON(o))); System.out.println(jsonArray.get(4)); System.out.println(jsonArray.getJSONArray(5).get(0)); System.out.println(jsonArray.get(5)); fail("==============Java String >>> JSON =================="); jsonArray = (JSONArray) xmlSerializer.read(xmlSerializer.write(JSONArray.fromObject("['json','is','easy']")).toString()); s = (String[]) JSONArray.toArray(jsonArray, String.class); fail(s[0].toString()); jsonObject = (JSONObject) xmlSerializer.read(xmlSerializer.write(JSONObject.fromObject("{'json':'is easy'}")).toString()); Object obj = JSONObject.toBean(jsonObject); System.out.println(obj); jsonArray = (JSONArray) xmlSerializer.read(xmlSerializer.write(JSONSerializer.toJSON("['json','is','easy']")).toString()); s = (String[]) JSONArray.toArray(jsonArray, String.class); fail(s[1].toString());}@Testpublic void testReadXml2Array() { String str = "<a class="array">" + "<e type="function" params="i,j">" + "return matrix[i][j];" + "</e>" + "</a>"; JSONArray json = (JSONArray) new XMLSerializer().read(str); fail(json.toString()); }