Spring注入service为null另类解决办法 工具类 一般类 静态 非controller

本文转载自：http://www.cnblogs.com/allforone/p/4108862.html

 系统为SpringMVC框架，在开发的过程中有一些工具类需要调用下由spring管理的service层。但是一进注入不进来，报null异常；

      在尝试了网上的一系列方法后，还是没有解决。网上的解决方法主要有以下几种：

        1、将工具类申明为spring组件，如@controller @compent 等，在spring自动扫描包设置中将工具类所在的包加进来；  无效  

        2、new一个service；  无效 而且不符合spring管理；

      山穷水尽后，找到了一个另类的解决办法，代码原理还不太清楚，只是大概猜测下，有错误的地方，大家留言指正：
@Component     //申明为spring组件
public class TestUtils {  

    @Autowired    
    private TestService testService;
 //添加所需service的私有成员
    private static
TestUtils  testUtils ;  //  关键点1   静态初使化 一个工具类  这样是为了在spring初使化之前
  
    public void setTestService(TestService  testService) {  
        this.testService
= testService;  
    }  
      
    @PostConstruct     //关键二
  通过@PostConstruct 和 @PreDestroy 方法 实现初始化和销毁bean之前进行的操作
    public void init() {  
        testUtils = this;  
        testUtils.testService = this.testService;
  // 初使化时将已静态化的testService实例化
    }  

                这样下面的代码中就可以通过 testUtils.testService 来调用service处理

实例代码

package com.common.common.util.model;

import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.alibaba.fastjson.JSONObject;
import com.common.common.util.BaseGateWay;
import com.common.common.util.SpringContextUtil;
import com.smart.entity.HomeDevice;
import com.smart.entity.HomeDeviceAttrStatu;
import com.smart.entity.HomeDeviceCommand;
import com.smart.entity.HomeDeviceLog;
import com.smart.entity.HomeGateway;
import com.smart.service.IHomeDeviceAttrStatuService;
import com.smart.service.IHomeDeviceLogService;
import com.smart.service.IHomeDeviceService;
import com.smart.service.IHomeGatewayService;
//网格报警器
@Component
public class GridAlarm implements BaseGateWay {
@Autowired
private IHomeDeviceService homeDeviceService ;
@Autowired
private IHomeDeviceLogService deviceLogService;
@Autowired
private IHomeDeviceAttrStatuService deviceAttrStatuService;
@Autowired
private IHomeGatewayService gatewayService;

private static GridAlarm util;

public void setHomeDeviceService(IHomeDeviceService homeDeviceService) {
this.homeDeviceService = homeDeviceService;
}
public void setDeviceLogService(IHomeDeviceLogService deviceLogService) {
this.deviceLogService = deviceLogService;
}
public void setDeviceAttrStatuService(
IHomeDeviceAttrStatuService deviceAttrStatuService) {
this.deviceAttrStatuService = deviceAttrStatuService;
}
public void setGatewayService(IHomeGatewayService gatewayService) {
this.gatewayService = gatewayService;
}

@PostConstruct
public void init(){
util =this;
util.deviceAttrStatuService = this.deviceAttrStatuService;
util.deviceLogService = this.deviceLogService;
util.gatewayService = this.gatewayService;
util.homeDeviceService = this.homeDeviceService;
}

@Override
public HomeDeviceCommand getHomeDeviceCommand(Map<String, Object> services) {
// TODO Auto-generated method stub
HomeDeviceCommand devCommandObj = new HomeDeviceCommand();
String command_type =" ";
String command_code =" ";
String comand =" ";
if(services.get("infrared_alarm")!=null){
//能力代码
command_type = "infrared_alarm";
//特征值代码
command_code = "alarm";
//更新网关布防状态
Map map = (Map)services.get(command_type);
comand = map.get(command_code).toString();
//不发短信
//issms = 0;
}
if(services.get("smoke_alarm")!=null){
//能力代码
command_type = "smoke_alarm";
//特征值代码
command_code = "alarm";
//更新网关布防状态
Map map = (Map)services.get(command_type);
comand = map.get(command_code).toString();
//不发短信
//issms = 0;
}
if(services.get("alarm_switch")!=null){
//能力代码
command_type = "alarm_switch";
//特征值代码
command_code = "on_off";
//更新网关布防状态
Map map = (Map)services.get(command_type);
comand = map.get(command_code).toString();
}
devCommandObj.setCommand(comand);
devCommandObj.setCommandType(command_type);
devCommandObj.setCommandCode(command_code);
return devCommandObj;
}

@Override
public void proceNotice(Map<String, Object> services,
List<HomeGateway> gatewayList, int gateway_id, String device_id_,
Integer device_code_, String gateway_uid, HomeDevice device_,
Integer device_type) {
// TODO Auto-generated method stub
if(services.get("operation_status")!=null){
Map map = (Map)services.get("operation_status");
if(gatewayList != null && gatewayList.size()>0){
if((int)map.get("status")==1){
this.UpdateRestOnLineDevice(gateway_id, device_id_, 1);
}else if((int)map.get("status")==-1){
//删除该子设备
Map<String, Object> maps = new HashMap<String, Object>();
maps.put("device_uid", device_id_);
maps.put("gateway_uid", gateway_uid);
maps.put("gateway_id", gateway_id);

util.homeDeviceService.deleteDeviceByUId(maps);
}else{
System.out.println("1234");
this.UpdateOffLineDevice(gateway_id, device_id_, 1);
}
}
}
if(services.get("alarm_switch")!=null){
//能力代码
String command_type = "alarm_switch";
//特征值代码
String command_code = "on_off";
//更新网关布防状态
Map map = (Map)services.get(command_type);
String comand = map.get(command_code).toString();

String desc = "布防";
if(comand.equals("0")){
desc = "撤防";
}
//保存日志
this.SaveDeviceLog(gateway_id, device_.getId(), comand, desc,gateway_uid,device_.getDeviceUid(),device_.getDeviceName());

this.SaveAlarmAttrStatus(device_.getId(), device_code_,command_type, command_code, comand, desc);

if(device_id_.equals(gateway_uid)&&device_code_ == device_type){
//网关修改布防撤防状态
Map<String,Object> maps = new HashMap<String,Object>();
int stat = 1;
if(Integer.parseInt(comand) == 0){
stat = 0;
}
maps.put("status", stat);
maps.put("gateway_uid", gateway_uid);
util.gatewayService.updateGatewayStatus(maps);
}
}

if(services.get("auto_alarm_time")!=null){ //定时警戒
//能力代码
String command_type = "auto_alarm_time";
//特征值代码
String command_code = "";

//更新网关布防状态
Map map = (Map)services.get(command_type);

String comand = JSONObject.toJSONString(map);
//保存日志
this.SaveDeviceLog(gateway_id, device_.getId(), command_type, comand,gateway_uid,device_.getDeviceUid(),device_.getDeviceName());

this.SaveAlarmAttrStatus(device_.getId(), device_code_,command_type, command_code, comand, "警戒时间");
}

}

//更新重新上线设备状态
private void UpdateRestOnLineDevice(int gatewayId,String deviceId,Integer typeCode) {
HomeDevice restOnLineDevObj = new HomeDevice();
restOnLineDevObj.setGatewayId(gatewayId);
restOnLineDevObj.setTypeCode(typeCode);
restOnLineDevObj.setDeviceUid(deviceId);
restOnLineDevObj.setStatus("1");
restOnLineDevObj.setUpTime(new Date());
util.homeDeviceService.updateDeviceOffLine(restOnLineDevObj);//更新重新上线设备状态
}
//更新掉线设备状态
private void UpdateOffLineDevice(int gatewayId,String deviceId,Integer typeCode) {
HomeDevice offLineDevObj = new HomeDevice();
offLineDevObj.setGatewayId(gatewayId);
offLineDevObj.setTypeCode(typeCode);
offLineDevObj.setDeviceUid(deviceId);
offLineDevObj.setStatus("0");
offLineDevObj.setUpTime(new Date());
util.homeDeviceService.updateDeviceOffLine(offLineDevObj);//更新掉线设备状态
}

//保存设备日志
private void SaveDeviceLog(int gatewayId,int deviceId,String command,String commandDesc,String gatewayUid,String deviceUid,String deviceName) {
//日志
//"type_code":"0103","device_uid":"3"
HomeDeviceLog devLogObj = new HomeDeviceLog();
devLogObj.setGatewayUid(gatewayUid);
devLogObj.setDeviceUid(deviceUid);
devLogObj.setDeviceName(deviceName);
devLogObj.setGatewayId(gatewayId);
devLogObj.setDeviceId(deviceId);
devLogObj.setMsgType("log");
devLogObj.setMsgCommand(command);
devLogObj.setMsgContent(commandDesc);
devLogObj.setCreatedTime(new Date());
devLogObj.setUpTime(new Date());
devLogObj.setDelFlag(0);
util.deviceLogService.insertDeviceLog(devLogObj);
}

//保存设备上报上来属性
public void SaveAlarmAttrStatus(int device_id,Integer type_code,String command_type,String command_code,String comand,String command_desc){

//保存到设备属性表中
HomeDeviceAttrStatu record = new HomeDeviceAttrStatu();
record.setDeviceId(device_id);
record.setTypeCode(type_code);
record.setCommandType(command_type);
record.setCommandCode(command_code);
record.setComand(comand);
record.setComandDesc(command_desc);
record.setCreatedTime(new Date());
record.setUpTime(new Date());
record.setDelFlag(0);

if(util.deviceAttrStatuService.selectExistsDeviceAttr(record)>0){
util.deviceAttrStatuService.updateDeviceAttr(record);
}else{
util.deviceAttrStatuService.insertDeviceAttr(record);
}
}

}