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。

以下仅仅说核心的部分，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，可是查找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，非常直白的写在了JS里：

   <script type="text/javascript">
        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 所相应的列表里的对象。

能够看出这个是一个数组，每一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/

能够依据JSON 字符串，生成相应的java类：

 类1

import java.util.List;

public class MessageList{
    private List<Message> msg_item;

	public List<Message> getMsg_item() {
		return msg_item;
	}

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

类2。部分字段没实用。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
}

以下来做个測试。

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。全部的对象都在 msgList里了