原来JAVA对象转JSON格式的字符串如此简单,返回来暂时不会做,留下纪念下

package info.moogens.mvc.tools.json;import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;/*** JSON操作类* 暂时仅仅支持将java对象转储成JSON格式的字符串* * 原来用的 Simple Json 中的JSONValue.toJSONString 不能渲染POJO对象, 无论是使用 元注释还是实现接口 * 或多或少的都存在移植依赖性的问题.* 而POLO对象会用在多个地方,诸如: 视图/数据库表映射[DAO]/服务层 等等* * 如果对象属于复合对象的话(非基本数据类型)可能存在效率问题,建议不使用多层次的POLO类* * @author KenXu* */
public final class JsonSpread {@SuppressWarnings("unchecked")public static String toJSONString(Object value) {if (value == null) return "null";if (value instanceof Number) return value.toString();if (value instanceof Boolean) return value.toString();if (value instanceof String)return "\"" + escape((String) value) + "\"";if (value instanceof Double) {if (((Double) value).isInfinite() || ((Double) value).isNaN())return "null";elsereturn value.toString();}if (value instanceof Float) {if (((Float) value).isInfinite() || ((Float) value).isNaN())return "null";elsereturn value.toString();}if (value instanceof Map) return map2Json((Map) value);if (value instanceof Collection) return coll2Json((Collection) value);if (value.getClass().isArray()) return array2Json(value);return pojo2Json(value);}static String array2Json(Object array) {if (null == array) return "null" ;StringBuffer sb = new StringBuffer();sb.append('[');// 此处减1是为了下面的 逗号 追加int len = Array.getLength(array) - 1;if (len > -1){int i ;for (i = 0; i < len; i++) {sb.append(toJSONString(Array.get(array, i))).append(", ");}sb.append(toJSONString(Array.get(array, i)));}sb.append(']');return sb.toString();}static String coll2Json(Collection<?> coll) {if (null == coll) return "null" ;StringBuffer sb = new StringBuffer();sb.append('[');for (Iterator<?> it = coll.iterator(); it.hasNext();) {sb.append(toJSONString(it.next()));if (it.hasNext())sb.append(", ");}sb.append(']');return sb.toString();};static String pojo2Json(Object obj) {Class<?> type = obj.getClass();Field[] fields = type.getDeclaredFields();Map<String, Object> map = new HashMap<String, Object>();for (Field f : fields) {if (Modifier.isStatic(f.getModifiers()))continue;String name = f.getName();f.setAccessible(true);Object value = null;try {value = f.get(obj);} catch (Exception e) {value = null;}map.put(name, value);}type = null;fields = null;return map2Json(map);}@SuppressWarnings("unchecked")static String map2Json(Map<String, Object> map) {if (null == map) return "null" ;StringBuffer sb = new StringBuffer();sb.append('{');for (Iterator<?> it = map.entrySet().iterator(); it.hasNext();) {Map.Entry entry=(Map.Entry)it.next();String key = (String)entry.getKey();if (null == key) continue ;sb.append('\"');escape(key,sb);sb.append('\"').append(':').append(toJSONString(entry.getValue()));if (it.hasNext())sb.append(", ");}sb.append('}');return sb.toString();};/*** Escape quotes, \, /, \r, \n, \b, \f, \t and other control characters (U+0000 through U+001F).* @param s* @return*/public static String escape(String s){if(s==null)return null;StringBuffer sb = new StringBuffer();escape(s, sb);return sb.toString();}	/*** @param s - Must not be null.* @param sb*/static void escape(String s, StringBuffer sb) {for (int i = 0; i < s.length(); i++) {char ch = s.charAt(i);switch (ch) {case '"':sb.append("\\\"");break;case '\\':sb.append("\\\\");break;case '\b':sb.append("\\b");break;case '\f':sb.append("\\f");break;case '\n':sb.append("\\n");break;case '\r':sb.append("\\r");break;case '\t':sb.append("\\t");break;case '/':sb.append("\\/");break;default:// Reference: http://www.unicode.org/versions/Unicode5.1.0/if ((ch >= '\u0000' && ch <= '\u001F')|| (ch >= '\u007F' && ch <= '\u009F')|| (ch >= '\u2000' && ch <= '\u20FF')) {String ss = Integer.toHexString(ch);sb.append("\\u");for (int k = 0; k < 4 - ss.length(); k++) {sb.append('0');}sb.append(ss.toUpperCase());} else {sb.append(ch);}}}}}

测试代码:

package info.moogens.mvc.tools.json;public final class User {private String name ,id;private Address ress ;public User(){this.name = "色色";this.id = "123";this.ress = new Address();this.ress.setCity("北京");this.ress.setZip(10086);}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getId() {return id;}public void setId(String id) {this.id = id;}public Address getRess() {return ress;}public void setRess(Address ress) {this.ress = ress;}}class Address {private String city;private int zip ;public String getCity() {return city;}public void setCity(String city) {this.city = city;}public int getZip() {return zip;}public void setZip(int zip) {this.zip = zip;}}

package info.moogens.mvc.tools.json;import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;import info.moogens.demo.pcmaster.Application;
import info.moogens.mvc.tools.Toolkit;
import info.moogens.mvc.web.UDI;public class X {/*** @param args*/public static void main(String[] args) {
//		System.out.println((String)null);System.out.println(Toolkit.toJson(UDI.parseUDIString("/book/show")));System.out.println(Toolkit.toJson(new Application()));System.out.println(Toolkit.toJson(new User()));List list = new ArrayList();list.add("abc我是");list.add(new Integer(123));list.add(new Double(222.123));list.add(new Boolean(true));list.add(null);Map map = new HashMap();map.put("name","fang");map.put("age",new Integer(27));map.put("is_developer",new Boolean(true));map.put("weight",new Double(60.21));map.put("user",new User());map.put("list",list);int[] array = new int[5];array[4] = 72 ; array[3] = 21 ; array[1] = 12 ; map.put("array",array);System.out.println(Toolkit.toJson(map));}}

测试结果:

写道

{"namespace":"default", "action":"show", "controller":"Book"}
{}
{"ress":{"zip":10086, "city":"北京"}, "name":"色色", "id":"123"}
{"list":["abc我是", 123, 222.123, true, null], "user":{"ress":{"zip":10086, "city":"北京"}, "name":"色色", "id":"123"}, "age":27, "is_developer":true, "name":"fang", "weight":60.21, "array":[0, 12, 0, 21, 72]}

反向的不会写反正有NUTZ的json 也用不到自己写,这个正向解析的基本可以用晚上回去想想怎么实现线程安全的

不知道性能怎么样啊