extjs中字符串和对象之间的转换，实现前后台传值

前台：

onRBtnClick : function(button, e, eOpts) {
		var form = button.up('form');
		var sampleNum = form.queryById('sampleNum').getValue();//获取组件属性值
		var sampleType = form.queryById('sampleType').getValue();
		var sampleDate = form.queryById('sampleDate').getValue();
		sampleDate = Ext.Date.format(sampleDate, 'Y-m-d');//日期转换

		var info = new Object();//new对象
		
                info .sampleNum = sampleNum;//把获取的值放入对象中

info.sampleType = sampleType;info.sampleDate = sampleDate;str = Ext.JSON.encode(info);//解析对象form.submit({url : 're/generate',method : 'post',params : {reportAdditionalInfo : str//传字符串到后台},success : function(form, action) {Ext.Msg.alert('信息提示', action, result.message);win.close();},failure : function(form, action) {Ext.Msg.alert('信息提示', action.result.message);}})},

后台：

public void generate(HttpServletRequest request, HttpServletResponse response,String info) {
		ObjectMapper objectMapper = new ObjectMapper();//new ObjectMapper
		ReportAdditionalInfo reportInfo = null;
		reportAdditionalInfo = StringEscapeUtils.unescapeHtml(reportAdditionalInfo);//不写会报错，解析出错
		try {
			reportInfo = objectMapper.readValue(reportAdditionalInfo, ReportAdditionalInfo.class);//readValue
		}  catch (IOException e1) {
			e1.printStackTrace();
		}
		
		String num = reportInfo.getNum();//获取值
		String type = reportInfo.getType();
		String date = reportInfo.getDate();

}