java 三大json解析性能对比（json-lib，gson，jackson）

        现在json的第三方的解析工具很多，我拿了3个比较常用的做了下简单的测试，发现jackson是大数据json的解析王者，也许这得力他基于流的方式。
        测试用列，10000000的json文本文件，一行是一个复杂的json对象如下：
        {"app":"yyhlweb","events":[{"type":"come","target":"com.youyuan.yyhl.activity.MainActivity","time":"2013-09-06 12:35:59"},{"type":"cbtn","target":"phoneBack","time":"2013-09-06 12:37:09"},{"type":"cbtn","target":"dialogExit","time":"2013-09-06 12:37:11"},{"type":"leave","target":"","time":"2013-09-06 12:37:11"}],"clientData":{"fid":"45001","platform":"android","os_ver":"4.2.2","imei":"356521051907413","userid":"117614041","ua":"GT-I9200","imsi":"460020394943982","resolution":"720x1280","net":"wifi","version":"40040003"}}
转成java对象，
    
        1.首先是gson：
       

    //10000000,565,891s
    @Test
    public void testComplex() throws IOException {
        long start = System.currentTimeMillis();
        String content = "";
        Gson gson = new GsonBuilder().create();
        while ((content = reader.readLine()) != null) {
            //System.out.println(content);
            Behaviour behaviour = gson.fromJson(content, Behaviour.class);
            //System.out.println(behaviour.getApp());
        }
        reader.close();
        System.out.println((System.currentTimeMillis() - start) + "ms");
    }

        gosn在处理一千万的的数据耗时565.891秒；

        2.然后是jackson，

        

    //10000000,57,963ms
    @Test
    public void testReadJsonToObject() throws JsonSyntaxException, IOException {
        long start = System.currentTimeMillis();
        String content = "";
        while ((content = reader.readLine()) != null) {
            //System.out.println(content);
            Behaviour behaviour = objectMapper.readValue(content, Behaviour.class);
            //System.out.println(behaviour.getApp());
        }
        System.out.println((System.currentTimeMillis() - start) + "ms");
    }

        jackson处理花了57.963秒，居然是gson的十倍，喔！


        3.接下来是json-lib: 
        这里面json-lib是比较老牌的解析技术了，使用起来也很方便，在使用上来说三者都很方便。

        

    //10000000,1498,733ms
    @Test
    public void testComplex() throws IOException {
        long start = System.currentTimeMillis();
        String content = "";
        JsonConfig config = new JsonConfig();
        config.setJavaIdentifierTransformer(new JavaIdentifierTransformer() {
          @Override
          public String transformToJavaIdentifier(String str) {
            char[] chars = str.toCharArray();
            chars[0] = Character.toLowerCase(chars[0]);
            return new String(chars);
          }
        });
        config.setRootClass(Behaviour.class);

        while ((content = reader.readLine()) != null) {
            //System.out.println(content);
            Behaviour behaviour = (Behaviour)JSONObject.toBean(JSONObject.fromObject(content,config), Behaviour.class);
            //System.out.println(behaviour.getEvents().size());
        }
        System.out.println((System.currentTimeMillis() - start) + "ms");
    }

        结果出来了，json-lib耗时1498.733秒，jackson在大数据的表现相当突出。