java - 将 DTO 转换为参数列表

Question

public class CreateCustomerRequest {
    private String fName;
    private String lName;
    private String gender;
    private String address1;
    private String address2;
    private String mobileNo;
}

我有上述请求 DTO。当我收到此请求时我需要什么然后我需要 convert this DTO with List<String> fields;哪里List<String> objects包含{fName, lName, gender, address1, address2, mobileNo}

请建议我如何实现这一目标。没有任何想法。

Answer 1

基于反射，如果您将字段公开，下面的代码可以工作，如果您想将它们设为私有(private)而不是设置字段，您可以通过构造函数将其转换。

public class CreateCustomerRequest {
    public String fName;
    public String lName;
    public String gender;
    public String address1;
    public String address2;
    public String mobileNo;
}


public static void main(String[] args) throws Throwable {
    List<String> param = new ArrayList<String>();
    param.add("fnameValue");
    param.add("lNameValue");
    param.add("genderValue");
    param.add("address1Value");
    param.add("address2Value");
    param.add("mobileNoValue");
    CreateCustomerRequest object = convert(param, CreateCustomerRequest.class);
    System.out.println("Gender : " + object.gender);
}

public static <T extends Object> T convert(List<String> param, Class<T> clazz) throws Throwable
{
    Constructor<?> ctor = clazz.getConstructor();
    T result = (T) ctor.newInstance();
    Field[] fields = result.getClass().getFields();
    if(fields == null)
        return null;
    for(int i =0;i<fields.length;i++)
    {
        if(fields[i].getType().equals(String.class))
        {
            if(param.size() > i)
                fields[i].set(result, param.get(i));
        }
    }       
    return result;
}

干杯。

编辑

为了将 DTO 类字段设为私有(private)并通过 getter 方法读取它们，我编辑了答案以支持它。

更改:

1. 将 result.getClass().getFields() ---> result.getClass().getDeclaredFields() 转换为能够读取私有(private)字段。
2. 在为字段设置值之前调用 fields[i].setAccessible(true)。
3. 通过 getter 读取字段值 --> System.out.println("Gender : "+ object.getGender());

所以 DTO 类的新代码是:

public class CreateCustomerRequest {
    private String fName;
    private String lName;
    private String gender;
    private String address1;
    private String address2;
    private String mobileNo;

    public String getfName() {
        return fName;
    }
    public void setfName(String fName) {
        this.fName = fName;
    }
    public String getlName() {
        return lName;
    }
    public void setlName(String lName) {
        this.lName = lName;
    }
    public String getGender() {
        return gender;
    }
    public void setGender(String gender) {
        this.gender = gender;
    }
    public String getAddress1() {
        return address1;
    }
    public void setAddress1(String address1) {
        this.address1 = address1;
    }
    public String getAddress2() {
        return address2;
    }
    public void setAddress2(String address2) {
        this.address2 = address2;
    }
    public String getMobileNo() {
        return mobileNo;
    }
    public void setMobileNo(String mobileNo) {
        this.mobileNo = mobileNo;
    }
}

转换代码是:

public static void main(String[] args) throws Throwable {
    List<String> param = new ArrayList<String>();
    param.add("fnameValue");
    param.add("lNameValue");
    param.add("genderValue");
    param.add("address1Value");
    param.add("address2Value");
    param.add("mobileNoValue");
    CreateCustomerRequest object = convert(param, CreateCustomerRequest.class);
    System.out.println("Gender : " + object.getGender());
}

public static <T extends Object> T convert(List<String> param, Class<T> clazz) throws Throwable
{
    Constructor<?> ctor = clazz.getConstructor();
    T result = (T) ctor.newInstance();
    Field[] fields = result.getClass().getDeclaredFields();
    if(fields == null)
        return null;

    for(int i =0;i<fields.length;i++)
    {           
        if(fields[i].getType().equals(String.class))
        {
            if(param.size() > i)
            {
                fields[i].setAccessible(true);
                fields[i].set(result, param.get(i));
            }
        }
    }       
    return result;
}