JavaWeb Form数据封装至Bean中工具类

最近在学JavaWeb,JSP提交Form表单数据通常封装至实体Bean中，再提交给Servlet，由于在Servlet中可以使用HttpServletRequest#getParameterMap() 得到Request中请求参数的Map集合，所以想通过Map中的值得到一个实体对象。

注意：定义实体的属性名要和Form表单标签的name属性值相同，同时Form表单传递来的数据都是String类型，可以不使用类型匹配条件。

格式：实体对象 toBean(map,实体对象.class)

1. 实体类：

package test;

import java.util.Date;

public class Person {

    private String name;

    private int age;

    private float salary;

    private double score;

    private Date date;

    private boolean flag;

    private Integer in;

    public Person(String name, int age, float salary, double score, Date date,
            boolean flag, Integer in) {
        super();
        this.name = name;
        this.age = age;
        this.salary = salary;
        this.score = score;
        this.date = date;
        this.flag = flag;
        this.in = in;
    }

    public Person() {
        super();
    }

    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 float getSalary() {
        return salary;
    }

    public void setSalary(float salary) {
        this.salary = salary;
    }

    public double getScore() {
        return score;
    }

    public void setScore(double score) {
        this.score = score;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    public boolean isFlag() {
        return flag;
    }

    public void setFlag(boolean flag) {
        this.flag = flag;
    }

    public Integer getIn() {
        return in;
    }

    public void setIn(Integer in) {
        this.in = in;
    }

    @Override
    public String toString() {
        return "Person [age=" + age + ", date=" + date + ", flag=" + flag
                + ", in=" + in + ", name=" + name + ", salary=" + salary
                + ", score=" + score + "]";
    }

}

2. 工具类，通过Java反射机制实现

package test;

import java.lang.reflect.Field;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

public class CommonUtil {

    public static <T> T toBean(Map<String, Object> map, Class<T> clazz) {

        if (map == null || map.size() <= 0) {
            return null;
        }
        T t = null;
        Set<Entry<String, Object>> entrySet = map.entrySet();
        try {
            t = clazz.newInstance();
            Field[] fields = clazz.getDeclaredFields();
            for (Entry<String, Object> entry : entrySet) {
                for (Field field : fields) {
                    field.setAccessible(true);
                    // 属性名
                    String fieldName = field.getName();
                    // 属性类型
                    String fieldType = field.getGenericType().toString();
                    System.out.println("属性名：" + fieldName + ", 属性类型："
                            + fieldType);
                    if (fieldType.contains("String")
                            && fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    } else if (fieldType.contains("int")
                            && fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    } else if (fieldType.contains("float")&& fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    } else if (fieldType.contains("double")&& fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    } else if (fieldType.contains("long")&& fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    } else if (fieldType.contains("byte")&& fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    } else if (fieldType.contains("Integer")&& fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    } else if (fieldType.contains("boolean")&& fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    }else if (fieldType.contains("Date")&& fieldName.equalsIgnoreCase(entry.getKey())) {
                        field.set(t, entry.getValue());
                    }
                }

            }
            System.out.println("t= " + t);
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

        return t;
    }

}

3 测试

package test;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import org.junit.Test;

public class TestUtil {

    @Test
    public void test() {
        Map<String,Object> map = new HashMap<String,Object>();
        map.put("name", "小黑");
        map.put("age", 11);
        map.put("date", new Date());
        map.put("flag",true);
        CommonUtil.toBean(map, Person.class);
    }

}

输出结果：
属性名：name, 属性类型：class java.lang.String
属性名：age, 属性类型：int
属性名：salary, 属性类型：float
属性名：score, 属性类型：double
属性名：date, 属性类型：class java.util.Date
属性名：flag, 属性类型：boolean
属性名：in, 属性类型：class java.lang.Integer
t= Person [age=11, date=Wed Nov 02 11:39:35 CST 2016, flag=true, in=null, name=小黑, salary=0.0, score=0.0]