jsondistrictservlet.java

关于Ajax的

package allan.ajax.action;

import allan.ajax.entity.District;
import allan.ajax.service.DistrictService;

public class JsonDistrictServlet extends DistrictServlet {

    protected String getInfo(String zipcode) {
        DistrictService districtService = new DistrictService();
        District district = districtService.getDistrict(zipcode);
        return getJsonData(district);
    }

    @Override
    protected String getContentType() {
        return "text/plain;charset=gbk";
    }

    protected String getJsonData(District district) {
        if (district == null) {
            district = new District();
        }

        StringBuilder builder = new StringBuilder();
        builder.append("{");
        builder.append("\"zipcode\":\"" + handleNull(district.getZipcode()) + "\",");
        builder.append("\"province\":\"" + handleNull(district.getProvince()) + "\",");
        builder.append("\"city\":\"" + handleNull(district.getCity()) + "\"");
        builder.append("}");

        return builder.toString();
    }

    protected String handleNull(String str) {
        if (str == null) {
            return "";
        }
        return str;
    }
}