程式碼如下

//dataPage物件包含了List<Statistictime>,此處想改變dataPage裡List裡Statistictime的內容
//將job_state欄位從code如yjs轉換為name如"已結束"
GroupJobService groupJobService = new GroupJobService();
//獲取code與name的對映如key="yjs",value="已結束"
Map<String, String> typeMapping = groupJobService.getTypeMapping();
List<Statistictime>
 
 list = dataPage.getList();
String jobState = null;
for (Statistictime statistictime : list) {
    jobState = statistictime.getStr("job_state");
    jobState = jobState!=null&&!"".equals(jobState.trim()) ? jobState.trim() : null;
    if(jobState!=null && typeMapping.containsKey(jobState)) {//typeMapping包含該key
 

        statistictime.set("job_state", typeMapping.get(jobState));
        statistictime.set("JOB_STATE", typeMapping.get(jobState));
    }
    jobState = null;
}

從上面程式碼可以看出,我們只是直接從dataPage獲取相應的List,並作出資料處理後並沒有將List放回dataPage裡,但dataPage的內容已經改變了,以下的簡單demo可以驗證

public class MyTest {
    @Test
    public
 
 void testIt() {
        A a = new A();
        a.setA(10);
        System.out.println(a.getA());
        go(a);
        System.out.println(a.getA());
    }
    public void go(A a) {
        a.setA(5);
    }
}
public class A{
    private int a;
    public void setA(int a){
        this.a=a;
    }
    public int getA(){
        return this.a;
    }
}

上面的程式碼的執行結果為:10,5
從而驗證了傳遞引用相當於傳遞指標的值,該值是物件在堆記憶體裡的地址.