爬虫-微信公众平台消息获取

帮朋友抓取微信公众平台的用户评论信息。

下面只说核心的部分，怎么获取评论信息。

查看HTML代码，没有发现关于评论部分的标签。看来是用JS动态生成的，但是查找ajax请求也没有找到哪里有返回数据。

最后搜索一下，原来是在这里，很直白的写在了JS里：

   
        wx.cgiData = {
            total_count : 91,
            latest_msg_id : '200325222',
            count : "20"*1 || 20,
            day : "7",
            frommsgid : "",
            can_search_msg : "1",
            offset : "",
            action : "",
            keyword : "",
            list : ({"msg_item":[{"id":200322761,"type":1,"fakeid":"593656935","nick_name":"Suang 1","date_time":1398854675,"content":"记得帮我查一下是不是这个电话！","source":"","msg_status":4,"has_reply":0,"refuse_reason":"","multi_item":[],"to_uin":3071594631,"send_stat":{"total":0,"succ":0,"fail":0}},{"id":200322760,"type":2,"fakeid":"593656935","nick_name":"Suang 1","date_time":1398854664,"source":"","msg_status":4,"has_reply":0,"refuse_reason":"","multi_item":[],"to_uin":3071594631,"send_stat":{"total":0,"succ":0,"fail":0}},{"id":200322759,"type":1,"fakeid":"593656935","nick_name":"Suang 1","date_time":1398854659,"content":"勐璇，我看到那人了！","source":"","msg_status":4,"has_reply":0,"refuse_reason":"","multi_item":[],"to_uin":3071594631,"send_stat":{"total":0,"succ":0,"fail":0}},{"id":200322344,"type":2,"fakeid":"1994400010","nick_name":"ABC的CBA","date_time":1398839849,"source":"","msg_status":4,"has_reply":0,"refuse_reason":"","multi_item":[],"to_uin":3071594631,"send_stat":{"total":0,"succ":0,"fail":0}},{"id":200321209,"type":1,"fakeid":"1591078101","nick_name":"倚(纺织服装)","date_time":1398788906,"content":"\/::<","source":"","msg_status":4,"has_reply":0,"refuse_reason":"","multi_item":[],"to_uin":3071594631,"send_stat":{"total":0,"succ":0,"fail":0}},{"id":200321206,"type":2,"fakeid":"1591078101","nick_name":"倚(纺织服装)","date_time":1398788859,"source":"","msg_status":4,"has_reply":1,"refuse_reason":"","multi_item":[],"to_uin":3071594631,"send_stat":{"total":0,"succ":0,"fail":0}},

用的是JSON格式，代码太乱，放在Eclipse里格式化一下，消息列表大概就是这个样了：

{"msg_item" :[ {
"id" : 200322761,
"type" : 1,
"fakeid" : "593656935",
"nick_name" : "Suang 1",
"date_time" : 1398854675,
"content" : "记得帮我查一下是不是这个电话！",
"source" : "",
"msg_status" : 4,
"has_reply" : 0,
"refuse_reason" : "",
"multi_item" : [],
"to_uin" : 3071594631,
"send_stat" : {
"total" : 0,
"succ" : 0,
"fail" : 0
}
}, {
"id" : 200322760,
"type" : 2,
"fakeid" : "593656935",
"nick_name" : "Suang 1",
"date_time" : 1398854664,
"source" : "",
"msg_status" : 4,
"has_reply" : 0,
"refuse_reason" : "",
"multi_item" : [],
"to_uin" : 3071594631,
"send_stat" : {
"total" : 0,
"succ" : 0,
"fail" : 0
}
}
]
}

上面就是 json字符串 中 msg_item 所对应的列表里的对象。

可以看出这个是一个数组，每个评论是里面的一个对象。怎么生成对于的Java类呢 ？

这里有一个在线的工具：http://jsongen.byingtondesign.com/

可以根据JSON 字符串，生成对应的java类：

 类1

import java.util.List;

public class MessageList{
    private List msg_item;

public List getMsg_item() {
return msg_item;
}

public void setMsg_item(List msgItem) {
msg_item = msgItem;
}
    
}

类2。部分字段没有用，删掉了

public class Message {

private String content;
private long date_time;
private String fakeid;
private int has_reply;
private long id;
private int msg_status;
private String nick_name;
private String refuse_reason;
private String source;
private long to_uin;
private int type;
// get set 略去
}

下面来做个测试。用google的 Gson 来进行处理，把json字符串解析为 java对象。

//jsonstr 为 msg_item 的json字符串
MessageList msgList = new Gson().fromJson(jsonstr, MessageList.class);
System.out.println(msgList.getMsg_item().size());

解析成功。所有的对象都在 msgList里了