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json解析我们不陌生了，不过每次编写解析的代码时总是很头疼，一堆很无聊的代码，如果有50个接口那就得写50个相似的解析处理。其实谷歌和阿里很早就推出了解析json的工具包，谷歌的Gson,阿里的FastJson，还有一个jackJson。有人说jackJson解析速度快，大数据时FastJson要比Gson效率高，小数据时反之。不过我还是偏爱谷歌的Gson，即使效率可能偏低，但是稳定性肯定没得说，FastJson和jackJson就不知道了。
现在我们来看看Json是如何解析的：
1.下载Gson开发包，放入工程libs目录下：
http://download.csdn.net/detail/itachi85/8617065
2.编写Bean文件：
先看一下json数据：
{
"array": [
{
"username": "在中",
"recommend": 0,
"user_photo": "0",
"like": false,
"reply_cnt": 3,
"distance": "2154m",
"add_date": "3天前",
"text": "肯德基快吃吐了，明天去麦当劳看看",
"stamp__name": null,
"place_id": 1,
"ptype": "d",
"like_cnt": "2",
"posting_image_url": "1",
"stamp_name": null,
"user": 0,
"stamp__id": null,
"dislike": "0",
"icon": "cate_icon_a_09",
"id": 0,
"mayor_cnt": 2,
"place_name": "东大桥肯德基",
"place_level": 2
},
{
"username": "在中",
"recommend": 0,
"user_photo": "0",
"like": false,
"reply_cnt": 0,
"distance": "2425m",
"add_date": "3天前",
"text": "这是在跳僵尸舞呢吗？",
"stamp__name": null,
"place_id": 7,
"ptype": "d",
"like_cnt": "0",
"posting_image_url": "0",
"stamp_name": null,
"user": 0,
"stamp__id": null,
"dislike": "0",
"icon": "cate_icon_b_05",
"id": 4,
"mayor_cnt": 2,
"place_name": "悠唐",
"place_level": 1
}
],
"error": 0,
"next": true
} 紧接着，我们创建bean文件
需要注意的是：
1、内部嵌套的类必须是static修饰的；
2、类里面的属性名必须跟Json字段里面的Key是一样的；
NearDynamic.java:
public class NearDynamic {
private Boolean next=false;
private int error;
private ArrayList<Dynamic> array = new ArrayList<Dynamic>();
public Boolean getNext() {
return next;
}
public void setNext(Boolean next) {
this.next = next;
}
public int getError() {
return error;
}
public void setError(int error) {
this.error = error;
}
public ArrayList<DynamicJ> getArray() {
return array;
}
public void setArray(ArrayList<DynamicJ> array) {
this.array = array;
}
}
上面包含了error，next字段，以及包含类型是Dynamic的List,接着我们创建Dynamic：
public class Dynamic {
private String username;
private int recommend;
private String user_photo;
private Boolean like;
private int replycnt;
private String distance;
private String add_date;
private String text;
private String stamp__name;
private int place_id;
private int like_cnt;
private String ptype;
private String posting_image_url;
private String stamp_name;
private int user;
private String stamp__id;
private int dislike=0;
private String icon;
private int id;
private String place_name;
private int place_level;
private String mayor_cnt;
public String getStamp__name() {
return stamp__name;
}
public void setStamp__name(String stamp__name) {
this.stamp__name = stamp__name;
}
public int getLike_cnt() {
return like_cnt;
}
public void setLike_cnt(int like_cnt) {
this.like_cnt = like_cnt;
}
public String getStamp_name() {
return stamp_name;
}
public void setStamp_name(String stamp_name) {
this.stamp_name = stamp_name;
}
public String getStamp__id() {
return stamp__id;
}
public void setStamp__id(String stamp__id) {
this.stamp__id = stamp__id;
}
public int getDislike() {
return dislike;
}
public void setDislike(int dislike) {
this.dislike = dislike;
}
public String getMayor_cnt() {
return mayor_cnt;
}
public void setMayor_cnt(String mayor_cnt) {
this.mayor_cnt = mayor_cnt;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getUser() {
return user;
}
public void setUser(int user) {
this.user = user;
}
public String getUsername() {
return username;
}
...
}3.使用Gson解析数据：
private int parseUserData() {
String strContent = Utils.getJson("neardynamic.txt");
if (!TextUtils.isEmpty(strContent)) {
try {
Gson mgson = new Gson();
NearDynamic mNearDynamic = mgson.fromJson(
strContent, NearDynamic.class);
ArrayList<Dynamic> mNearDynamicList = mNearDynamic
.getArray();
LogController.i(mNearDynamicList.get(1).getUsername());
return BaseEngine.RESULT_OK;
} catch (Exception e) {
e.printStackTrace();
return BaseEngine.PARSEJSON_ERR;
}
}
return BaseEngine.RESULT_ERR;
}
上面代码是一个解析的方法：直接从txt文件中读取数据由Json解析，首先由Json生成NearDynamic,然后得到array中的列表数据，我们取第二个数据打下log，得出的结果是"在中",解析完毕。
如果想要快速测试的话，就写一个txt文件，里面写有json数据，放入assets文件中，然后用下面的方法读取txt文件中数据，再按照上面所讲的就可以了：
public static String getJson(String filename) {
InputStream mInputStream = null;
String resultString = "";
try {
mInputStream = App.mContext.getAssets().open(filename);
byte[] buffer = new byte[mInputStream.available()];
mInputStream.read(buffer);
resultString = new String(buffer, "GB2312");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
try {
mInputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return resultString.toString();
}想要了解Gson更多的方法可以下载http://download.csdn.net/detail/itachi85/8617065中的文件，里面有Gson的文档。
原文地址：http://blog.csdn.net/itachi85/article/details/45172205
