創建類的新的實例，作爲字符串和更新設置方法

Question

即時通訊類名（字符串）和類有幾個方法和 因爲它的動態（我可以得到任何類）我需要使用所有set方法並用數據更新它。 我該怎麼做？

要獲取類的字段我用下面的代碼

className = obj.getClassName(); 
Class<?> classHandle = Class.forName(className); 

例如這裏我需要更新firstName和姓氏

public class Person { 

private String id; 
    private String firstName; 
    private String lastName; 

    public void setLastName(String lastName) { 

     this.lastName = lastName; 
    } 

    public void setfirstName(String firstName) { 

     this.firstName = firstName; 
    } 

或不同類在這裏，我需要設置工資和工作描述

public class Job { 


    private double salery; 
    private String jobDescr; 


    public void setSalery(double salery) { 
    this.salery = salery; 
    } 

    public void setJobDescr(String jobDescr) { 
    this.jobDescr = jobDescr; 
    } 

} 

Answer 1

對於初學者來說，你做的很好。我假設你有一個Map<String, Object>的屬性設置：attributeMap。

//this is OK 
className = obj.getClassName(); 
Class<?> classHandle = Class.forName(className); 

//got the class, create an instance - no-args constructor needed! 
Object myObject = classHandle.newInstance(); 

//iterate through all the methods declared by the class 
for(Method method : classHandle.getMethods()) { 
    //check method name 
    if(method.getName().matches("set[A-Z].*") 
     //check if it awaits for exactly one parameter 
     && method.getParameterTypes().length==1) { 

     String attributeName = getAttributeName(method.getName()); 
     //getAttributeName would chop the "set", and lowercase the first char of the name of the method (left out for clarity) 

     //To be extra nice, type checks could be inserted here... 
     method.invoke(myObject, attributeMap.get(attributeName));    

    } 
} 

當然，很多異常處理是必須要做的，這是什麼做只是一個基本的想法...

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• Class
• Class.getMethods()
• Method
• Method.invoke()