extjs +String2 +Spring 下的分页 以及返回json格式错误的问题

首先,分页  很简单.

1前台extjs数据源,

var shipMgrStore = Ext.create('Ext.data.Store', {
    model: 'App.ShipMgr.model.ShipModel',
    autoLoad: true,
    pageSize: 15,
//   timeout: 300000,
//    simpleSortMode:true,
    proxy: {
        type: 'ajax',
        url:'<%=request.getContextPath()%>/getDuncanJiang.action',
        reader: {
            reader: 'json',
            root: 'sfdcConfigList',
            totalProperty: 'totalProperty'
        },
    },
});

其他的属性就不说了.

主要是两个参数:一个是   root  :表示接收到的数据从这个   sfdcConfigLIst  开始解析

　　　　             一个是 totalProperty   :表示返回数据的总行数

2 grid

var shipMgrGrid = Ext.create('Ext.grid.Panel', {
    store: shipMgrStore,
    columnLines: true,
    rowLines: true,
    region: 'center',
    autoScroll: true,
    forceFit: true,
     loadMask: true,
     border: true,
    renderTo:'showPanel',
    bbar: Ext.create('Ext.toolbar.Paging', {
        id:'<portlet:namespace />bbar',
        store: shipMgrStore,
        pageSize:15,
        displayInfo: true
    }),
    columns: [
        Ext.create('Ext.grid.RowNumberer', {
            text: 'numbr',
            50
        }), {
            text: 'id',
            dataIndex: 'id'
        }
        , {
            text: 'plant',
            dataIndex: 'plant'
        }, {
            text: 'deviceId',
            dataIndex: 'deviceId'
        }, {
            text: 'sfdcPort',
            dataIndex: 'sfdcPort'
        }, {
            text: 'description',
            dataIndex: 'description'
        }
    ],
    bbar: Ext.create('Ext.toolbar.Paging', {
            id: '<portlet:namespace />duncanjiangbbar',
            pageSize: 15,
        store: shipMgrStore,
        displayInfo: true,
        displayMsg: '<%= bundle.getString("message.records") %> {0} - {1} of {2}',
        emptyMsg: '<%= bundle.getString("page.nodata") %>'
    })
});

传递二个参数 limit : 每页显示多少条 (pageSize)

　　　　　　 start :从第几条数据开始 (自动传递)

　　当你在前台点击下一页的时候,它就会自动把 limit 和 start 传到后台查询数据,然后返回对面页的数据过来

后台的话 



   private int start;
	　　//get  set
   private int limit;


　　//get set


public String findSfdcByDeviceId(){
        try {
            int limit=this.limit;
            int start=this.start;
　　　　// 根据传过来的参数,查询数据
    　　this.fileNameList=testService.getSfdcCOnfigObjbyDeviceId(type,start,limit);
   　　 //总条数
        totalProperty=testService.getSfdcCOunt(type);
        
}




其实就是 返回 两个数据集,一个是  fileNameList,当页数据, totalPropery是总共有多少条数据.


               定义属性接收前台传过来的 limit,start,并且生成get,set方法



&&&&&&&&&&&&&&&我是傲娇的分割线&&&&&&&&&&&&&&&&&&&&&&&


 然后做这个分页的时候还遇上一个问题,返回的 JSON数据到前台的时候报了一个错




html><head><title>Apache Tomcat/7.0.39 - Error report</title><style><!--H1 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:22px;} H2 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:16px;} H3 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:14px;} BODY {font-family:Tahoma,Arial,sans-serif;color:black;background-color:white;} B {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;} P {font-family:Tahoma,Arial,sans-serif;background:white;color:black;font-size:12px;}A {color : black;}A.name {color : black;}HR {color : #525D76;}--></style> </head><body><h1>HTTP Status 500 - org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper with modifiers &quot;public&quot;</h1><HR size="1" noshade="noshade"><p><b>type</b> Exception report</p><p><b>message</b> <u>org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper with modifiers &quot;public&quot;</u></p><p><b>description</b> <u>The server encountered an internal error that prevented it from fulfilling this request.</u></p><p><b>exception</b> <pre>org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.IllegalAccessException: Class org.apache.struts2.json.JSONWriter can not access a member of class org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper with modifiers &quot;public&quot;
    org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:243)
    org.apache.struts2.json.JSONWriter.process(JSONWriter.java:165)
    org.apache.struts2.json.JSONWriter.value(JSONWriter.java:131)
    org.apache.struts2.json.JSONWriter.write(JSONWriter.java:99)
    org.apache.struts2.json.JSONUtil.serialize(JSONUtil.java:112)
    org.apache.struts2.json.JSONResult.execute(JSONResult.java:198)
    com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:362)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:266)
    com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:165)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:252)
    org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:179)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:94)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)
    org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:235)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:237)





这个是由于后台返回前台的数据中,会包含所有的get开头的,包括你的get属性,get开头的方法等等等等.导致的问题.


解决 : 1.在这些不需要返回的get方法的前面加上@JSON(serialize=false)这个注解.


　　   2.把查询返回的数据集做一个简单的处理,通过gson进行解析.具体为什么要这样....我也不清楚..... 哈哈哈哈,反正这样就可以了




public String findSfdcByDeviceId(){
        try {
            int limit=this.limit;
            int start=this.start;
            this.fileNameList=testService.getSfdcCOnfigObjbyDeviceId(type,start,limit);
            Gson gson=new Gson();  
            List<SfdcConfigObj> rs=new ArrayList<SfdcConfigObj>();  
            String str=JSONArray.fromObject(fileNameList).toString();
            Type  ortype = new TypeToken<ArrayList<SfdcConfigObj>>() {}.getType();  
              rs=gson.fromJson(str, ortype);
              for(SfdcConfigObj sfdc : rs){  
                  sfdcConfigList.add(sfdc);
              }

            totalProperty=testService.getSfdcCOunt(type);

        } catch (Exception e) {
            e.printStackTrace();
        }
        
        return Action.SUCCESS;
    }






注意!!!   如果你要返回的,比如一个属性,暂且叫他为   number.这时候他的get方法如果你也加了这个注解的话,那么前台是获取不到这个值的.





        

	      

	    

	  

	  

	    
      
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          原文地址：https://www.cnblogs.com/jdw12306/p/7494362.html