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查找嵌套类的所有私有字段及其对应的getter / setter

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情况:很少有应用程序使用Java DTO进行通信 . 我有一些类作为其字段保存另一个类,并且它们还包含另一个类(从顶部DTO最多三个级别) .

字段可以是单个DTO,也可以是(仅限)其他类(DTO)的ArrayList . 所有课程都是DTO . 只是私人领域和公共制定者和吸气剂 .

现在,当我得到顶级DTO有任何方法来检查它并获得所有的getter,包括嵌套的,通过getter读取字段然后做我必须做的事情(更改一些数据,特别是删除/更改一些字符(我有方法)这样做,所有最终字段最终都是字符串或整数),然后使用适当的setter写回数据 . 我想最好的是找到每个最终字段的getter / setter对,然后进行操作然后移到next . 找到final(最低级别字段)我应该检查它是否是String(执行操作)和Integer跳过操作 .

我知道有类似的问题,但它不涉及嵌套的DTO . Java reflection get all private fields

如果可能的话,我会避免使用任何第三方库 .

有什么建议吗?

更新:几乎在那里 . 这是一种演示代码,我希望它是如此简单,但在概念上它更像是:

专题讨论会.DTO

import java.util.ArrayList;

public class SymposiaDTO {
    private ProgramDTO programDTO;
    private ArrayList<PaperDTO> papersDTO;

    public ProgramDTO getProgramDTO() {
    return programDTO;
    }

    public void setProgramDTO(ProgramDTO programDTO) {
    this.programDTO = programDTO;
    }

    public ArrayList<PaperDTO> getPapersDTO() {
    return papersDTO;
    }

    public void setPapersDTO(ArrayList<PaperDTO> papersDTO) {
    this.papersDTO = papersDTO;
    }
}

类ProgramDTO

public class ProgramDTO {
    String programTitle;

    Integer programID;

    public String getProgramTitle() {
    return programTitle;
    }

    public void setProgramTitle(String programTitle) {
    this.programTitle = programTitle;
    }

    public Integer getProgramID() {
    return programID;
    }

    public void setProgramID(Integer programID) {
    this.programID = programID;
    }
}

PaperDTO课程

import java.util.ArrayList;

public class PaperDTO {
    public String getTitle() {

    return title;
    }

    public void setTitle(String title) {
    this.title = title;
    }

    public ArrayList<AuthorDTO> getAuthrosDTO() {
    return authrosDTO;
    }

    public void setAuthrosDTO(ArrayList<AuthorDTO> authrosDTO) {
    this.authrosDTO = authrosDTO;
    }

    private String title;
    private ArrayList<AuthorDTO> authrosDTO;
}

类AuthorDTO

public class AuthorDTO {
    private String address;
    private String name;

    private String title;
    private String age;

    public String getAddress() {
    return address;
    }

    public void setAddress(String address) {
    this.address = address;
    }

    public String getName() {
    return name;
    }

    public void setName(String name) {
    this.name = name;
    }

    public String getTitle() {
    return title;
    }

    public void setTitle(String title) {
    this.title = title;
    }

    public String getAge() {
    return age;
    }

    public void setAge(String age) {
    this.age = age;
    }
}

class Controller <---由Carlos如果我的说法正确,这个版本根本没有输出,甚至没有在for循环中进行单次迭代 .

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

public class Controller {
    @SuppressWarnings({ "unused", "rawtypes" })
    public static void main(String[] args) {

    SymposiaDTO symposiaDTO = new SymposiaDTO();
    ProgramDTO programDTO = new ProgramDTO();
    PaperDTO paperDTO = new PaperDTO();
    AuthorDTO authorDTO = new AuthorDTO();

    Class<?> topClass = symposiaDTO.getClass();
    for (Class<?> innerClass : topClass.getDeclaredClasses()) {
        for (Field field : innerClass.getDeclaredFields()) {
        if (Modifier.isPrivate(field.getModifiers())) {
            String name = Character.toUpperCase(field.getName().charAt(0)) + field.getName().substring(1);
            Method getter;
            try {
            getter = innerClass.getDeclaredMethod("get" + name);
            } catch (Exception ex) {
            getter = null;
            }
            Method setter;
            try {
            setter = innerClass.getDeclaredMethod("set" + name, field.getType());
            } catch (Exception ex) {
            setter = null;
            }

            // TODO real work...
            System.out.printf("%s: getter=%s, setter=%s%n", innerClass.getSimpleName(), getter, setter);
        }
        }
    }
    }
}

类Controller2 <---略微修改了以前的版本,这进入了循环,但运行了两次,并且它永远不会深入到嵌套的DTO中 .

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Controller2 {
    @SuppressWarnings({ "unused", "rawtypes" })
    public static void main(String[] args) {
    SymposiaDTO symposiaDTO = new SymposiaDTO();
    ProgramDTO programDTO = new ProgramDTO();
    PaperDTO paperDTO = new PaperDTO();
    AuthorDTO authorDTO = new AuthorDTO();

    Class<?> topClass = symposiaDTO.getClass();
    List<Class> classesToWalk = new ArrayList<Class>();

    for (Field field : topClass.getDeclaredFields()) {
        Class symposiaDTO2 = field.getDeclaringClass();
        classesToWalk.add(symposiaDTO2);
    }

    for (Class<?> innerClass : classesToWalk) {
        Field[] fields = Arrays.stream(innerClass.getDeclaredFields())
            .filter(field -> Modifier.isPrivate(field.getModifiers())).toArray(Field[]::new);
        for (Field field : fields) {
        String name = Character.toUpperCase(field.getName().charAt(0)) + field.getName().substring(1);
        Method getter;
        try {
            getter = innerClass.getDeclaredMethod("get" + name);
        } catch (Exception ex) {
            getter = null;
        }
        Method setter;
        try {
            setter = innerClass.getDeclaredMethod("set" + name, field.getType());
        } catch (Exception ex) {
            setter = null;
        }
        // TODO real work...
        System.out.printf("%s: getter=%s, setter=%s%n", innerClass.getSimpleName(), getter, setter);
        }
    }
    }
}

这是从Controller2输出的:

SymposiaDTO:getter = public ProgramDTO SymposiaDTO.getProgramDTO(),setter = public void SymposiaDTO.setProgramDTO(ProgramDTO)SymposiaDTO:getter = public java.util.ArrayList SymposiaDTO.getPapersDTO(),setter = public void SymposiaDTO.setPapersDTO(java.util .ArrayList)SymposiaDTO:getter = public ProgramDTO SymposiaDTO.getProgramDTO(),setter = public void SymposiaDTO.setProgramDTO(ProgramDTO)SymposiaDTO:getter = public java.util.ArrayList SymposiaDTO.getPapersDTO(),setter = public void SymposiaDTO.setPapersDTO(java .util.ArrayList)

1 回答

  • 2

    您可以使用 getDeclaredClasses 查找嵌套类,然后找到私有字段,最后找到getter和setter:

    Class<?> topClass = ...
    
    for (Class<?> innerClass : topClass.getDeclaredClasses()) {
        for (Field field : innerClass.getDeclaredFields()) {
            if (Modifier.isPrivate(field.getModifiers())) {
                String name = Character.toUpperCase(field.getName().charAt(0)) 
                            + field.getName().substring(1);
                Method getter;
                try {
                    getter = innerClass.getDeclaredMethod("get" + name);
                } catch (Exception ex) {
                    getter = null;
                }
                Method setter;
                try {
                    setter = innerClass.getDeclaredMethod("set" + name, field.getType());
                } catch (Exception ex) {
                    setter = null;
                }
    
                // TODO real work...
                System.out.printf("%s: getter=%s, setter=%s%n", 
                                  innerClass.getSimpleName(), getter, setter);
            }
        }
    }
    

    Edit :上述代码对问题 Headers 中提到的"nested classes"有效 . 将示例代码添加到问题后,似乎问题是关于类的字段的getter和setter:

    使用 getDeclaredFields 获取类的所有字段并找到相应的getter和setter,如上所示;使用 getType 获取每个字段的类型(类),并(递归地)重新开始该类 .

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