FastJson---高性能JSON开发包

发布时间：2020-12-16 18:54:26 所属栏目：百科来源：网络整理

导读：参考：http://git.oschina.net/eric_ds/jfire-codejson Fastjson介绍 Fastjson是一个Java语言编写的JSON处理器,由阿里巴巴公司开发。 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JavaBe

参考：http://git.oschina.net/eric_ds/jfire-codejson

Fastjson介绍

Fastjson是一个Java语言编写的JSON处理器,由阿里巴巴公司开发。
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
5、具有超高的性能，java世界里没有其他的json库能够和fastjson可相比了。

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

如果你使用了Maven，maven repository配置如下：

<span style="font-size:13px"><repository>
	<id>opensesame</id>
	<name>Alibaba OpenSource Repsoitory</name>
	<url>http:</span><span class="code-comment" style="color:#808080;background-color:inherit"><span style="font-size:13px">//code.alibabatech.com/mvn/releases/</url>
</span></span><span style="font-size:13px">	<snapshots>
		<enabled></span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">false</span></span><span style="font-size:13px"></enabled>
	</snapshots>
</repository>
</span>

pom.xml文件中加入依赖依赖：

<span style="font-size:13px"><dependency>
	<groupId>com.alibaba</groupId>
	<artifactId>fastjson</artifactId>
	<version>1.0.4</version>
</dependency>
</span>

如果没有使用maven，可以直接下载：

Binary :http://code.alibabatech.com/mvn/releases/com/alibaba/fastjson/1.1.1/fastjson-1.1.1.jar
Source :http://code.alibabatech.com/mvn/releases/com/alibaba/fastjson/1.1.1/fastjson-1.1.1-sources.jar
Subversion :http://code.alibabatech.com/svn/fastjson/

使用介绍：
Fastjson的最主要的使用入口是com.alibaba.fastjson.JSON

<span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">import</span></span><span style="font-size:13px"> com.alibaba.fastjson.JSON;

</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">static</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">final</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Object</span></span><span style="font-size:13px"> parse(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> text); </span><span class="code-comment" style="color:#808080;background-color:inherit"><span style="font-size:13px">// 把JSON文本parse为JSONObject或者JSONArray
</span></span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">static</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">final</span></span><span style="font-size:13px"> JSONObject parSEObject(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> text)； </span><span class="code-comment" style="color:#808080;background-color:inherit"><span style="font-size:13px">// 把JSON文本parse成JSONObject
</span></span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">static</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">final</span></span><span style="font-size:13px"> <T> T parSEObject(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> text,</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Class</span></span><span style="font-size:13px"><T> clazz); </span><span class="code-comment" style="color:#808080;background-color:inherit"><span style="font-size:13px">// 把JSON文本parse为JavaBean
</span></span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">static</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">final</span></span><span style="font-size:13px"> JSONArray parseArray(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> text); </span><span class="code-comment" style="color:#808080;background-color:inherit"><span style="font-size:13px">// 把JSON文本parse成JSONArray
</span></span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">static</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">final</span></span><span style="font-size:13px"> <T> List<T> parseArray(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> text,</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Class</span></span><span style="font-size:13px"><T> clazz); </span><span class="code-comment" style="color:#808080;background-color:inherit"><span style="font-size:13px">//把JSON文本parse成JavaBean集合
</span></span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">static</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">final</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> toJSONString(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Object</span></span><span style="font-size:13px"> object); </span><span class="code-comment" style="color:#808080;background-color:inherit"><span style="font-size:13px">// 将JavaBean序列化为JSON文本
</span></span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">static</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">final</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> toJSONString(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Object</span></span><span style="font-size:13px"> object,</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">boolean</span></span><span style="font-size:13px"> prettyFormat); </span><span class="code-comment" style="color:#808080;background-color:inherit"><span style="font-size:13px">// 将JavaBean序列化为带格式的JSON文本
</span></span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">static</span></span><span style="font-size:13px"> </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">final</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Object</span></span><span style="font-size:13px"> toJSON(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Object</span></span><span style="font-size:13px"> javaObject); 将JavaBean转换为JSONObject或者JSONArray。
</span>

代码示例：
代码示例用到类User和Group：

<span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> class User {
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">private</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Long</span></span><span style="font-size:13px"> id;
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">private</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> name;

	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Long</span></span><span style="font-size:13px"> getId() { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">return</span></span><span style="font-size:13px"> id; }
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> void setId(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Long</span></span><span style="font-size:13px"> id) { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">this</span></span><span style="font-size:13px">.id = id; }

	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> getName() { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">return</span></span><span style="font-size:13px"> name; }
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> void setName(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> name) { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">this</span></span><span style="font-size:13px">.name = name; }
}
</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> class Group {
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">private</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Long</span></span><span style="font-size:13px"> id;
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">private</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> name;
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">private</span></span><span style="font-size:13px"> List<User> users = </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">new</span></span><span style="font-size:13px"> ArrayList<User>();

	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Long</span></span><span style="font-size:13px"> getId() { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">return</span></span><span style="font-size:13px"> id; }
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> void setId(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">Long</span></span><span style="font-size:13px"> id) { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">this</span></span><span style="font-size:13px">.id = id; }

	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> </span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> getName() { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">return</span></span><span style="font-size:13px"> name; }
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> void setName(</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> name) { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">this</span></span><span style="font-size:13px">.name = name; }

	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> List<User> getUsers() { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">return</span></span><span style="font-size:13px"> users; }
	</span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">public</span></span><span style="font-size:13px"> void setUsers(List<User> users) { </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">this</span></span><span style="font-size:13px">.users = users; }
}
</span>

Encode代码示例：

<span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">import</span></span><span style="font-size:13px"> com.alibaba.fastjson.JSON;

Group group = </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">new</span></span><span style="font-size:13px"> Group();
group.setId(0L);
group.setName(</span><span class="code-quote" style="color:#0910;background-color:inherit"><span style="font-size:13px">"admin"</span></span><span style="font-size:13px">);

User guestUser = </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">new</span></span><span style="font-size:13px"> User();
guestUser.setId(2L);
guestUser.setName(</span><span class="code-quote" style="color:#0910;background-color:inherit"><span style="font-size:13px">"guest"</span></span><span style="font-size:13px">);

User rootUser = </span><span class="code-keyword" style="color:#0091;background-color:inherit"><span style="font-size:13px">new</span></span><span style="font-size:13px"> User();
rootUser.setId(3L);
rootUser.setName(</span><span class="code-quote" style="color:#0910;background-color:inherit"><span style="font-size:13px">"root"</span></span><span style="font-size:13px">);

group.getUsers().add(guestUser);
group.getUsers().add(rootUser);

</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">String</span></span><span style="font-size:13px"> jsonString = JSON.toJSONString(group);

</span><span class="code-object" style="color:#91091;background-color:inherit"><span style="font-size:13px">System</span></span><span style="font-size:13px">.out.println(jsonString);
</span>

Decode 代码示例：

<span style="font-size:13px">Group group2 = JSON.parSEObject(jsonString,Group.class);
</span>

之前的一个版本是1.1.0，1.1.0采用asm和SortFastMatch算法提高性能，由于过于着急展示其优越的性能，没有进行严格测试就发布了。

1.1.1相对于1.1.0，这是一个比较稳定的版本了，行测试覆盖率重新提升到90%以上，build verify testcase 983个。

这个版本进一步完善了asm和SortFieldFastMatch算法，进一步提升了性能，同时补充了大量的testcase，提升了稳定性，我向你推荐使用这个版本，使用这个版本你将会得到令人惊奇的性能。

1.1.1版本的asm来源自objectweb的asm项目，根据fastjson的需要做裁剪，确保引入asm的同时不引起包大小的过渡变大。

为了更好使用sort field martch优化算法提升parser的性能，fastjson序列化的时候，缺省把SerializerFeature.SortField特性打开了。反序列化的时候也缺省把SortFeidFastMatch的选项打开了。这样，如果你用fastjson序列化的文本，输出的结果是按照fieldName排序输出的，parser时也能利用这个顺序进行优化读取。这种情况下，parser能够获得非常好的性能。

我使用github.com/eishay/jvm-serializers/提供的程序做测试，性能数据如下：

hessianprotobufthriftavrojson-libjacksonfastjson

	序列化时间	反序列化时间	大小	压缩后大小
java序列化	8546	43199	889	541
6643	10043	501	313
3008	1694	239	149
3182	1951	349	197
3575	2095	221	133
45734	149741	485	263
3245	2986	503	271
2292	1499	468	251

测试跑的脚本是：

<span style="font-size:13px">./run -chart -include=`cat serializers.txt | tr </span><span class="code-quote" style="color:#0910;background-color:inherit"><span style="font-size:13px">"n"</span></span><span style="font-size:13px"> </span><span class="code-quote" style="color:#0910;background-color:inherit"><span style="font-size:13px">","</span></span><span style="font-size:13px">`  data/media.1.cks
</span>

从上面的数据来看，fastjson的性能已经超越protobuf、thrift、avro这些二进制协议了。一个文本协议的性能超越二进制协议是很难的，我很高兴向大家宣布我做到了！！

鉴于fastjson优越的性能表现，我建议做如下事情；
1、替换其他所有的json库，java世界里没有其他的json库能够和fastjson可相比了。
2、使用fastjson的序列化和反序列化替换java serialize，java serialize不单性能慢，而且体制大。
3、使用fastjson替换hessian，json协议不必hessian体积大，而且fastjson性能优越，数倍于hessian
4、把fastjson用于memached缓存对象数据。

How to get it?

If you're Maven user,just use our maven repository(http://code.alibabatech.com/mvn/releases/) with folloging dependency

<span style="font-size:13px"><dependency>
     <groupId>com.alibaba</groupId>
     <artifactId>fastjson</artifactId>
     <version>1.1.1</version>
</dependency>
</span>

Downlaods

Binary :http://code.alibabatech.com/svn/fastjson/

（编辑：李大同）

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