gson ajax 数字精度丢失
ajax传输的json，gson会发生丢失，long > 15的时候会丢失0
解决方案：直接把属性为long的属性自动加上双引号成为js的字符串，这样就不会发生丢失了，ajax自动识别为字符串。
用法:
ajaxResult("",0,new Object()); //随便一个对象就可以，List
/**
* 以Ajax方式输出常规操作结果
*
* @param status
* 返回状态，200表示成功, 500表示错误
* @param message
* 操作结果描述
* @param tag
* 附加数据
* @return
*/
protected ActionResult ajaxResult(int status, final String message, Object tag) {
JsonObject json = new JsonObject();
json.addProperty("status", status);
json.addProperty("message", message);
String strJson = json.toString();
if (tag != null) {
StringBuffer sb = new StringBuffer();
sb.append(strJson.substring(0, strJson.length() - 1));
sb.append(",\"tag\":");
sb.append(GsonUtils.toJsonWithGson(tag));
sb.append("}");
strJson = sb.toString();
}
return writeJson(strJson);
}
/**
* 向客户端输出文本信息
*
* @param message
* @return
*/
protected ActionResult write(final String message) {
return new ActionResult() {
@Override
public void render(BeatContext arg0) throws Exception {
beat.getResponse().setCharacterEncoding("UTF-8");
beat.getResponse().setContentType("text/json;charset=UTF-8");
PrintWriter out = beat.getResponse().getWriter();
out.print(message);
out.close();
}
};
}
/**
* 向客户端输出文本信息
*
* @param message
* @return
*/
protected ActionResult writeText(final String message) {
return new ActionResult() {
@Override
public void render(BeatContext arg0) throws Exception {
beat.getResponse().setCharacterEncoding("UTF-8");
beat.getResponse().setContentType("application/text");
PrintWriter out = beat.getResponse().getWriter();
out.print(message);
out.close();
}
};
}
GsonUtils.java
package com.xxx.xxx.common.util.gson;
import com.google.gson.*;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
public class GsonUtils {
//private static Log logger = LogFactory.getLog(GsonUtils.class);
public static String toJsonWithGson(Object obj) {
Gson gson = createGson(); //new Gson();
return gson.toJson(obj);
}
public static String toJsonWithGson(Object obj, Type type) {
Gson gson = createGson(); //new Gson();
return gson.toJson(obj, type);
}
@SuppressWarnings("unchecked")
public static String toJsonWithGson(List list) {
Gson gson = createGson(); //new Gson();
return gson.toJson(list);
}
@SuppressWarnings("unchecked")
public static String toJsonWithGson(List list, Type type) {
Gson gson = createGson(); //new Gson();
return gson.toJson(list, type);
}
public static String toJsonWithGsonBuilder(Object obj) {
Gson gson = new GsonBuilder().setExclusionStrategies(new MyExclusionStrategy()).serializeNulls().create();
return gson.toJson(obj);
}
public static String toJsonWithGsonBuilder(Object obj, Type type) {
Gson gson = new GsonBuilder().setExclusionStrategies(new MyExclusionStrategy()).serializeNulls().create();
return gson.toJson(obj, type);
}
@SuppressWarnings("unchecked")
public static String toJsonWithGsonBuilder(List list) {
Gson gson = new GsonBuilder().setExclusionStrategies(new MyExclusionStrategy()).serializeNulls().create();
return gson.toJson(list);
}
@SuppressWarnings("unchecked")
public static String toJsonWithGsonBuilder(List list, Type type) {
Gson gson = new GsonBuilder().setExclusionStrategies(new MyExclusionStrategy()).serializeNulls().create();
return gson.toJson(list, type);
}
public static <T> Object fromJson(String json, Class<T> clazz) {
Object obj = null;
try {
Gson gson = new Gson();
obj = gson.fromJson(json, clazz);
} catch (Exception e) {
//logger.error("fromJson方法转换json串到实体类出错", e);
}
return obj;
}
/**
* 如果 Long 的数字超过15位，转换为String，在json中数字两边有引号
* @return
*/
private static Gson createGson(){
GsonBuilder gsonBuilder = new GsonBuilder();
LongSerializer serializer = new LongSerializer();
gsonBuilder.registerTypeAdapter(Long.class, serializer);
gsonBuilder.registerTypeAdapter(long.class, serializer);
Gson gson = gsonBuilder.create();
return gson;
}
public static void main(String... args) throws Exception{
// long a = 12345678901234578L;
//
// GsonBuilder builder = new GsonBuilder();
// builder.registerTypeAdapter(Long.class, new LongSerializer());
// Gson gson2 = builder.create();
// System.out.println(gson2.toJson(a));
//
// Gson gson = new GsonBuilder().setExclusionStrategies(new MyExclusionStrategy()).serializeNulls().create();
// String str = gson.toJson(a);
// System.out.println(str);
TestVO vo = new TestVO();
vo.setId(618708732263538688L);
vo.setId2(918708732263538688L);
System.out.println(toJsonWithGson(vo));
}
static class LongSerializer implements JsonSerializer<Long> {
public JsonElement serialize(Long src, Type typeOfSrc, JsonSerializationContext context) {
if(src!=null){
String strSrc = src.toString();
if(strSrc.length()>15){
return new JsonPrimitive(strSrc);
}
}
return new JsonPrimitive(src);
}
}
static class TestVO {
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
private long id;
public Long getId2() {
return id2;
}
public void setId2(Long id2) {
this.id2 = id2;
}
private Long id2;
}
}
MyExclusionStrategy.java
package com.xxx.xxx.common.util.gson;
import com.google.gson.ExclusionStrategy;
import com.google.gson.FieldAttributes;
public class MyExclusionStrategy implements ExclusionStrategy {
private final Class<?> typeToSkip;
public MyExclusionStrategy(){
this.typeToSkip=null;
}
public MyExclusionStrategy(Class<?> typeToSkip) {
this.typeToSkip = typeToSkip;
}
public boolean shouldSkipClass(Class<?> clazz) {
return (clazz == typeToSkip);
}
public boolean shouldSkipField(FieldAttributes f) {
return f.getAnnotation(NotSerialize.class) != null;
}
}
NotSerialize
package com.xxx.xxx.common.util.gson;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.FIELD})
public @interface NotSerialize {
}
