java反射，模拟解析字符串数据_java 反射解析字符串-优快云博客

该博客介绍了一种通过读取文件内容，利用Java的内省机制将字符串数据解析并封装到Girl类实例中的方法。首先，读取文件内容并分割处理，然后通过反射调用Girl类的setter方法设置属性值。最后，创建并输出了两个Girl对象的实例，展示了封装后的结果。

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字符串数据
在这里插入图片描述
将上面的字符串数据解析并封装

Girl类

public class Girl {

    private String name;
    private int age;
    private Date birthday;

    public Girl() {
    }

    public Girl(String name, int age, Date birthday) {
        this.name = name;
        this.age = age;
        this.birthday = birthday;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

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

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
        age = new Date().getYear() - birthday.getYear();
    }

    @Override
    public String toString() {
        return "Girl{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", birthday=" + birthday +
                '}';
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Girl girl = (Girl) o;
        return age == girl.age && Objects.equals(name, girl.name) && Objects.equals(birthday, girl.birthday);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, age, birthday);
    }
}

开始

1、读取文件内的内容

        File file = new File("object.txt");
        FileInputStream fileInputStream = new FileInputStream(file);
        String str = null;
        byte[] bytes = new byte[1024];
        int len = 0;

		while ((len = fileInputStream.read(bytes)) != -1){
            str = new String(bytes,0,len);
        }

2、用字符串的方法将读取到的内容进行处理

		String split05 = null;
        String split06 = null;
        String split07 = null;
        String split08 = null;

        String[] split01 = null;

        split01 = str.split("\r\n");
        for (String split02 : split01) {
            String[] split03 = split02.split(";");
            for (String split04 : split03) {
                if (split04.contains(":")){
                    split05 = split04.split(":")[1].split("=")[0];
                    split06 = split04.split(":")[1].split("=")[1];
                }else {
                    split07 = split04.split("=")[0];
                    split08 = split04.split("=")[1];
                    try {
                        parse = simpleDateFormat.parse(split08);
                    } catch (ParseException e) {
                        e.printStackTrace();
                    }
                }
             }
         }

3、利用内省机制将得到的数据封装

		int i = 1;

        BeanInfo beanInfo = Introspector.getBeanInfo(Girl.class);
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

                for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
                    if (propertyDescriptor.getName().equals(split05)){
                        Method writeMethod = propertyDescriptor.getWriteMethod();
                        if (i == 1){
                            writeMethod.invoke(girl,split06);
                        }else if (i == 2){
                            writeMethod.invoke(girl2,split06);
                        }
                    }else if(propertyDescriptor.getName().equals(split07)){
                        Method writeMethod = propertyDescriptor.getWriteMethod();
                        if (i == 1){
                            writeMethod.invoke(girl,parse);
                            i++;
                        }else if (i == 2){
                            writeMethod.invoke(girl2,parse);
                        }
                    }
                }

4、我们还需要两个实例化的Girl

        Girl girl = Girl.class.newInstance();
        Girl girl2 = Girl.class.newInstance();

5、在解析时需要将时间一并解析

        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Date parse = null;

6、效果

Girl{name='张三', age=26, birthday=Mon Jan 02 00:00:00 CST 1995}
Girl{name='李四', age=22, birthday=Mon Feb 01 00:00:00 CST 1999}

源代码

import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;

public class ParseObject {
    public static void main(String[] args) throws IOException, IllegalAccessException, InstantiationException, IntrospectionException, InvocationTargetException {

        File file = new File("D:\\Reflect project\\Reflect\\src\\object.txt");
        FileInputStream fileInputStream = new FileInputStream(file);
        String str = null;
        byte[] bytes = new byte[1024];
        int len = 0;

        Girl girl = Girl.class.newInstance();
        Girl girl2 = Girl.class.newInstance();

        BeanInfo beanInfo = Introspector.getBeanInfo(Girl.class);
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Date parse = null;

        String split05 = null;
        String split06 = null;
        String split07 = null;
        String split08 = null;

        String[] split01 = null;

        int i = 1;

        while ((len = fileInputStream.read(bytes)) != -1){
            str = new String(bytes,0,len);
        }

        split01 = str.split("\r\n");
        for (String split02 : split01) {
            String[] split03 = split02.split(";");
            for (String split04 : split03) {
                if (split04.contains(":")){
                    split05 = split04.split(":")[1].split("=")[0];
                    split06 = split04.split(":")[1].split("=")[1];
                }else {
                    split07 = split04.split("=")[0];
                    split08 = split04.split("=")[1];
                    try {
                        parse = simpleDateFormat.parse(split08);
                    } catch (ParseException e) {
                        e.printStackTrace();
                    }
                }

                for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
                    if (propertyDescriptor.getName().equals(split05)){
                        Method writeMethod = propertyDescriptor.getWriteMethod();
                        if (i == 1){
                            writeMethod.invoke(girl,split06);
                        }else if (i == 2){
                            writeMethod.invoke(girl2,split06);
                        }
                    }else if(propertyDescriptor.getName().equals(split07)){
                        Method writeMethod = propertyDescriptor.getWriteMethod();
                        if (i == 1){
                            writeMethod.invoke(girl,parse);
                            i++;
                        }else if (i == 2){
                            writeMethod.invoke(girl2,parse);
                        }
                    }
                }
            }
        }
        System.out.println(girl);
        System.out.println(girl2);
    }
}