FastJSON是一个很好的java开源json工具类库,相比其他同类的json类库,它的速度的确是fast,最快!但是文档做得不好,在应用前不得不亲测一些功能。
实际上其他的json处理工具都和它差不多,api也有几分相似。
一、JSON规范
JSON是一个标准规范,用于数据交互,规范的中文文档如下:
http://www.json.org/json-zh.html
参看规范,来对比JSON类库处理结果。
二、fastjson的一些简要说明
1、了解fastjson
Fastjson介绍
Fastjson是一个Java语言编写的JSON处理器。
1、遵循 http://json.org标准,为其官方网站收录的参考实现之一。
2、功能qiang打,支持JDK的各种类型,包括基本的JavaBean、Collection、Map、Date、Enum、泛型。
3、无依赖,不需要例外额外的jar,能够直接跑在JDK上。
4、开源,使用Apache License 2.0协议开源。 http://code.alibabatech.com/wiki/display/FastJSON/Home
如果获得Fastjson?
SVN: http://code.alibabatech.com/svn/fastjson/trunk/
WIKI: http://code.alibabatech.com/wiki/display/FastJSON/Home
Issue Tracking: http://code.alibabatech.com/jira/browse/FASTJSON
2、主要的使用入口
Fastjson API入口类是com.alibaba.fastjson.JSON,常用的序列化操作都可以在JSON类上的静态方法直接完成。
public static final Object parse(String text);
// 把JSON文本parse为JSONObject或者JSONArray public static final JSONObject parseObject(String text);
// 把JSON文本parse成JSONObject public static final T parseObject(String text, Class clazz);
// 把JSON文本parse为JavaBean public static final JSONArray parseArray(String text);
// 把JSON文本parse成JSONArray public static final List parseArray(String text, Class clazz);
//把JSON文本parse成JavaBean集合 public static final String toJSONString(Object object);
// 将JavaBean序列化为JSON文本 public static final String toJSONString(Object object,
boolean prettyFormat);
// 将JavaBean序列化为带格式的JSON文本 public static final Object toJSON(Object javaObject); 将JavaBean转换为JSONObject或者JSONArray。
3、有关类库的一些说明
SerializeWriter:相当于StringBuffer
JSONArray:相当于List
JSONObject:相当于Map
JSON反序列化没有真正数组,本质类型都是List
4、fastjson还有很多很高级的特性,比如支持注解、支持全类型序列化,这些都是很好的特性,功能强大,不在本次测试范围。
三、测试代码
package lavasoft.stu.json;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializeConfig;
import com.alibaba.fastjson.serializer.SimpleDateFormatSerializer;
import java.util.*;
/** * Created by IntelliJ IDEA. * * @author leizhimin 11-11-22 上午9:15 */ public class Foo {
private String vString =
"vStringhehhehe" ;
private char vchar = 'x';
private byte vbyte = 64;
private short vshort = 128;
private int vint = 65535;
private long vlong = 9999999L;
private float vfloat = 12.1f;
private double vdouble = 22.203d;
private boolean vboolean =
false ;
// private Date vdate = new Date();
private Date dddd =
new Date();
private Date vDate =
new Date();
private Date v_Date =
new Date();
private Object vnull =
null ;
private String[] avString = {
"aaa" ,
"bbb" ,
"ccc" };
private int [] avint = {1, 2, 3, 4};
private boolean [] avboolean = {
true ,
false ,
true ,
true };
private List listString =
new ArrayList();
private Map map =
new HashMap();
private Bar bar =
new Bar();
private Bar[] avBar = {
new Bar(),
new Bar()};
private List listBar =
new ArrayList();
{
listString.add(
"listString1" );
listString.add(
"listString2" );
listString.add(
"listString3" );
map.put(
"x" ,
"s11111x" );
map.put(
"y" ,
"s22222y" );
map.put(
"z" ,
"s33333z" );
listBar.add(
new Bar());
listBar.add(
new Bar());
listBar.add(
new Bar());
}
public String getvString() {
return vString;
}
public void setvString(String vString) {
this .vString = vString;
}
public char getVchar() {
return vchar;
}
public void setVchar(
char vchar) {
this .vchar = vchar;
}
public byte getVbyte() {
return vbyte;
}
public void setVbyte(
byte vbyte) {
this .vbyte = vbyte;
}
public short getVshort() {
return vshort;
}
public void setVshort(
short vshort) {
this .vshort = vshort;
}
public int getVint() {
return vint;
}
public void setVint(
int vint) {
this .vint = vint;
}
public long getVlong() {
return vlong;
}
public void setVlong(
long vlong) {
this .vlong = vlong;
}
public float getVfloat() {
return vfloat;
}
public void setVfloat(
float vfloat) {
this .vfloat = vfloat;
}
public double getVdouble() {
return vdouble;
}
public void setVdouble(
double vdouble) {
this .vdouble = vdouble;
}
public boolean isVboolean() {
return vboolean;
}
public void setVboolean(
boolean vboolean) {
this .vboolean = vboolean;
}
public Date getDddd() {
return dddd;
}
public void setDddd(Date dddd) {
this .dddd = dddd;
}
public Date getV_Date() {
return v_Date;
}
public void setV_Date(Date v_Date) {
this .v_Date = v_Date;
}
public Date getvDate() {
return vDate;
}
public void setvDate(Date vDate) {
this .vDate = vDate;
}
public Object getVnull() {
return vnull;
}
public void setVnull(Object vnull) {
this .vnull = vnull;
}
public String[] getAvString() {
return avString;
}
public void setAvString(String[] avString) {
this .avString = avString;
}
public int [] getAvint() {
return avint;
}
public void setAvint(
int [] avint) {
this .avint = avint;
}
public boolean [] getAvboolean() {
return avboolean;
}
public void setAvboolean(
boolean [] avboolean) {
this .avboolean = avboolean;
}
public List getListString() {
return listString;
}
public void setListString(List listString) {
this .listString = listString;
}
public Map getMap() {
return map;
}
public void setMap(Map map) {
this .map = map;
}
public Bar getBar() {
return bar;
}
public void setBar(Bar bar) {
this .bar = bar;
}
public Bar[] getAvBar() {
return avBar;
}
public void setAvBar(Bar[] avBar) {
this .avBar = avBar;
}
public List getListBar() {
return listBar;
}
public void setListBar(List listBar) {
this .listBar = listBar;
}
}
package lavasoft.stu.json;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializeConfig;
import com.alibaba.fastjson.serializer.SimpleDateFormatSerializer;
import java.util.Date;
import java.util.Random;
/** * Created by IntelliJ IDEA. * * @author leizhimin 11-11-22 上午9:15 */ public class Bar {
public static SerializeConfig mapping =
new SerializeConfig();
private String barName;
private int barAge;
private Date barDate =
new Date();
static {
mapping.put(Date.
class ,
new SimpleDateFormatSerializer(
"yyyy-MM-dd" ));
}
{
Random r =
new Random();
barName =
"sss_" +String.valueOf(r.nextFloat());
barAge = r.nextInt();
}
public static void main(String[] args) {
Object obj = JSON.toJSON(
new Bar());
String x1 = JSON.toJSONString(
new Bar(),
true );
System.out.println(x1);
String x2 = JSON.toJSONString(
new Bar(), mapping);
System.out.println(x2);
}
public String getBarName() {
return barName;
}
public void setBarName(String barName) {
this .barName = barName;
}
public int getBarAge() {
return barAge;
}
public void setBarAge(
int barAge) {
this .barAge = barAge;
}
public Date getBarDate() {
return barDate;
}
public void setBarDate(Date barDate) {
this .barDate = barDate;
}
@Override
public String toString() {
return "Bar{" +
"barName='" + barName + '\'' +
", barAge=" + barAge +
", barDate=" + barDate +
'}';
}
}
package lavasoft.stu.json;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.serializer.SerializeConfig;
import com.alibaba.fastjson.serializer.SimpleDateFormatSerializer;
import java.util.*;
/** * Created by 2IntelliJ IDEA. * * @author leizhimin 11-11-22 上午9:45 */ public class Test {
private static SerializeConfig mapping =
new SerializeConfig();
static {
mapping.put(Date.
class ,
new SimpleDateFormatSerializer(
"yyyy-MM-dd HH:mm:ss" ));
}
public static void main(String[] args) {
Foo f1 =
new Foo();
Date date =
new Date();
String text = JSON.toJSONString(date, mapping);
System.out.println(text);
System.out.println(JSON.toJSONString(f1,
true ));
String x2 =JSON.toJSONString(f1, mapping);
System.out.println(x2);
}
public static void json2List(){
//List -> JSON array List barList =
new ArrayList();
barList.add(
new Bar());
barList.add(
new Bar());
barList.add(
new Bar());
String json= JSON.toJSONString(barList,
true );
System.out.println(json);
//JSON array -> List List barList1 = JSON.parseArray(json,Bar.
class );
for (Bar bar : barList1) {
System.out.println(bar.toString());
}
}
public static void json2Map(){
//Map -> JSON Map map =
new HashMap();
map.put(
"a" ,
new Bar());
map.put(
"b" ,
new Bar());
map.put(
"c" ,
new Bar());
String json = JSON.toJSONString(map,
true );
System.out.println(json);
//JSON -> Map Map map1 = (Map)JSON.parse(json);
for (String key : map1.keySet()) {
System.out.println(key+
":" +map1.get(key));
}
}
public static void array2JSON(){
String[] arr_String = {
"a" ,
"b" ,
"c" };
String json_arr_String = JSON.toJSONString(arr_String,
true );
System.out.println(json_arr_String);
JSONArray jsonArray = JSON.parseArray(json_arr_String);
for (Object o : jsonArray) {
System.out.println(o);
}
System.out.println(jsonArray);
}
public static void array2JSON2(){
Bar[] arr_Bar = {
new Bar(),
new Bar(),
new Bar()};
String json_arr_Bar = JSON.toJSONString(arr_Bar,
true );
System.out.println(json_arr_Bar);
JSONArray jsonArray = JSON.parseArray(json_arr_Bar);
for (Object o : jsonArray) {
System.out.println(o);
}
System.out.println(jsonArray);
}
public static void map2JSON(){
Map map =
new HashMap();
map.put(
"a" ,
"aaa" );
map.put(
"b" ,
"bbb" );
map.put(
"c" ,
"ccc" );
String json=JSON.toJSONString(map);
System.out.println(json);
Map map1 = JSON.parseObject(json);
for (Object o : map.entrySet()) {
Map.Entry entry = (Map.Entry)o;
System.out.println(entry.getKey()+
"--->" +entry.getValue());
}
}
}
说明:
SerializeConfig:是对序列化过程中一些序列化过程的特殊配置,这里用作日期格式的定义。
有关需要带类型的全类型序列化过程,需要调用JSON.toJSONStringZ()方法。
需要美化输出时候,需要打开序列化美化开关,在方法中true那个参数。
输出结果:
"2011-11-23 23:30:33"
{
"avBar":[{
"barAge":174398800,
"barDate":1322062233062,
"barName":"sss_0.62378174"
},{
"barAge":38938962,
"barDate":1322062233062,
"barName":"sss_0.36014742"
}],
"avString":["aaa","bbb","ccc"],
"avboolean":[true,false,true,true],
"avint":[1,2,3,4],
"bar":{
"barAge":1601495948,
"barDate":1322062233062,
"barName":"sss_0.46644872"
},
"dddd":1322062233046,
"listBar":[
{
"barAge":-1090113522,
"barDate":1322062233062,
"barName":"sss_0.83562374"
},
{
"barAge":478603194,
"barDate":1322062233062,
"barName":"sss_0.59483266"
},
{
"barAge":1118357669,
"barDate":1322062233062,
"barName":"sss_0.9961642"
}
],
"listString":[
"listString1",
"listString2",
"listString3"
],
"map":{"x":"s11111x","y":"s22222y","z":"s33333z"},
"v_Date":1322062233046,
"vboolean":false,
"vbyte":64,
"vchar":"x",
"vdouble":22.203,
"vfloat":12.1,
"vint":65535,
"vlong":9999999,
"vshort":128
}
{"avBar":[{"barAge":174398800,"barDate":"2011-11-23 23:30:33","barName":"sss_0.62378174"},{"barAge":38938962,"barDate":"2011-11-23 23:30:33","barName":"sss_0.36014742"}],"avString":["aaa","bbb","ccc"],"avboolean":[true,false,true,true],"avint":[1,2,3,4],"bar":{"barAge":1601495948,"barDate":"2011-11-23 23:30:33","barName":"sss_0.46644872"},"dddd":"2011-11-23 23:30:33","listBar":[{"barAge":-1090113522,"barDate":"2011-11-23 23:30:33","barName":"sss_0.83562374"},{"barAge":478603194,"barDate":"2011-11-23 23:30:33","barName":"sss_0.59483266"},{"barAge":1118357669,"barDate":"2011-11-23 23:30:33","barName":"sss_0.9961642"}],"listString":["listString1","listString2","listString3"],"map":{"x":"s11111x","y":"s22222y","z":"s33333z"},"v_Date":"2011-11-23 23:30:33","vboolean":false,"vbyte":64,"vchar":"x","vdouble":22.203,"vfloat":12.1,"vint":65535,"vlong":9999999,"vshort":128}
Process finished with exit code 0
fastjson通过各方面测试都很好,功能性能都是No.1,喜欢,它的源代码质量很高,作者也煞费苦心,将性能做到了最好,全免超越其他的json类库。
从其中的源代码中,可以学到很多东西,在阅读源码后,不得不佩服作者高超的程序设计水平,和高质量的编码。
这是关于FastJson的一个使用Demo,在Java环境下验证的
class User{
private int id;
private String name;
public int getId() {
return id;
}
public void setId( int id) {
this .id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this .name = name;
}
}
import java.util.ArrayList;
import java.util.List;
class Group{
private int id;
private String name;
private List list = new ArrayList();
public int getId() {
return id;
}
public void setId( int id) {
this .id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this .name = name;
}
public List getList() {
return list;
}
public void setList(List list) {
this .list = list;
}
}
class Weibo {
private String id;
private String city;
public Weibo(String id, String city) {
this .id = id;
this .city = city;
}
public Weibo() {
}
public String getId() {
return id;
}
public void setId(String id) {
this .id = id;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this .city = city;
}
}
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
public class JsonDemo {
public static void main(String[] args) {
json2JsonObjectM1();
json2BeanM2();
json2JSONArrayM3();
json2JavaBeanM4();
bean2JsonM5();
bean2JSONObjectM6();
complexExampleM7();
complex2JsonM8();
complexMap2JsonM9();
}
private static void json2JsonObjectM1() {
String s = "{\"name\":\"liuzhao\"}" ;
JSONObject object = JSON.parseObject(s);
System.out.println(object.get("name" ));
}
private static void json2BeanM2() {
String s = "{\"id\":\"0375\",\"city\":\"平顶山\"}" ;
Weibo weibo = JSON.parseObject(s, Weibo.class );
System.out.println(weibo.getId());
System.out.println(weibo.getCity());
}
private static void complexMap2JsonM9() {
Group group = new Group();
group.setId(1 );
group.setName("group" );
User user1 = new User();
user1.setId(2 );
user1.setName("user1" );
User user2 = new User();
user2.setId(3 );
user2.setName("user2" );
group.getList().add(user1);
group.getList().add(user2);
Map map = new HashMap();
map.put(1 , "No.1" );
map.put(2 , "No.2" );
map.put(3 , group.getList());
String jsonString = JSON.toJSONString(map);
System.out.println(jsonString);
}
private static void complex2JsonM8() {
Group group = new Group();
group.setId(1 );
group.setName("group" );
User user1 = new User();
user1.setId(2 );
user1.setName("user1" );
User user2 = new User();
user2.setId(3 );
user2.setName("user2" );
group.getList().add(user1);
group.getList().add(user2);
String jsonString = JSON.toJSONString(group);
System.out.println(jsonString);
}
private static void complexExampleM7() {
String s = "{js:[{id:\"110000\",\"city\":\"北#001京市\"},{id:\"110000\",\"city\":\"北#002京市\"}"
+ ",{id:\"110000\",\"city\":\"北#002京市\"},{id:\"110000\",\"city\":\"北#002京市\"},"
+ "{id:\"110000\",\"city\":\"#006北#005京市\"},"
+ "{id:\"110000\",\"city\":\"北#002京市\"},"
+ "{id:\"110000\",\"city\":\"北#002京市\"},{id:\"120000\",\"city\":\"天#009津市\"}]}" ;
JSONObject object = JSON.parseObject(s);
Object jsonArray = object.get("js" );
System.out.println(jsonArray);
List list = JSON.parseArray(jsonArray+"" , Weibo. class );
for (Weibo weibo : list) {
System.out.println(weibo.getCity());
}
}
private static void bean2JSONObjectM6() {
Weibo weibo = new Weibo( "0373" , "洛阳" );
JSONObject json = (JSONObject) JSON.toJSON(weibo);
System.out.println(json.get("id" ));
}
private static void json2JavaBeanM4() {
String s = "[{\"id\":\"0375\",\"city\":\"平顶山\"},{\"id\":\"0377\",\"city\":\"南阳\"}]" ;
List list = JSON.parseArray(s, Weibo.class );
for (Weibo weibo : list) {
System.out.println(weibo.getCity());
}
}
private static void json2JSONArrayM3() {
String s = "[{\"id\":\"0375\",\"city\":\"平顶山\"},{\"id\":\"0377\",\"city\":\"南阳\"}]" ;
JSONArray array = JSON.parseArray(s);
String str = array.get(1 )+ "" ;
System.out.println(array.get(0 ));
JSONObject object = JSON.parseObject(str);
System.out.println(object.get("id" ));
}
private static void bean2JsonM5() {
Weibo weibo = new Weibo( "123456" , "上海" );
String string = JSON.toJSONString(weibo);
System.out.println(string);
}
}