Spring框架基础之注解

自定义注解并且实现一些功能

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package cn.itcast.shujujiegou.StructuresAnalysis;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;/** * Created by likailong on 2016/9/29. */@Retention(RetentionPolicy.RUNTIME)@Target(ElementType.FIELD)public @interface Column {    String name();}

package cn.itcast.shujujiegou.StructuresAnalysis;import java.util.Date;/** * Created by likailong on 2016/9/29. */public class UserDo {    @Column(name="name")    private String userName;    @Column(name="title")    private String userTitle;    @Column(name="time")    private int loginTime;    private int intnum;    private String empId;    private Date dateTime;    public Date getDateTime() {        return dateTime;    }    public void setDateTime(Date dateTime) {        this.dateTime = dateTime;    }    public int getIntnum() {        return intnum;    }    public void setIntnum(int intnum) {        this.intnum = intnum;    }    public String getUserName() {        return userName;    }    public void setUserName(String userName) {        this.userName = userName;    }    public String getUserTitle() {        return userTitle;    }    public void setUserTitle(String userTitle) {        this.userTitle = userTitle;    }    public int getLoginTime() {        return loginTime;    }    public void setLoginTime(int loginTime) {        this.loginTime = loginTime;    }    public String getEmpId() {        return empId;    }    public void setEmpId(String empId) {        this.empId = empId;    }}

实现封数据方法

package cn.itcast.shujujiegou.StructuresAnalysis;import java.beans.IntrospectionException;import java.beans.PropertyDescriptor;import java.beans.PropertyEditor;import java.beans.PropertyEditorManager;import java.lang.reflect.Field;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;import java.lang.reflect.Modifier;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;import java.util.LinkedList;import java.util.List;import java.util.Map;/** * Created by likailong on 2016/9/29. * 目前对date数据不能处理 */public class MethodBean {    public final static SimpleDateFormat DEFAULT_DATE_FORMAT=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");    public static <T> T converMapToBean(Map<String,String> row,Class<T> clazz) throws IllegalAccessException, InstantiationException, NoSuchMethodException, IntrospectionException, InvocationTargetException, ParseException {        Object object=clazz.newInstance();        List<Field> list=findFields(clazz);        for(Field field:list){            if(!Modifier.isStatic(field.getModifiers())&&!Modifier.isFinal(field.getModifiers())){                if(!field.isAccessible()){                    field.setAccessible(true);                    Column column = field.getAnnotation(Column.class);                    if(column!=null){                        String value=row.get(column.name());                        Class<?> fieldtype = field.getType();                        if(fieldtype==String.class){                            field.set(object,value);                        }else if(fieldtype==Integer.class){                            field.set(object,getInteger(value));                        }else if(fieldtype==int.class){                            field.setInt(object,getInt(value));                        }else if(fieldtype==Long.class){                            field.set(object,getLongWropper(value));                        }else if(fieldtype==long.class){                            field.setLong(object,getLong(value));                        }else if(fieldtype==double.class){                            field.set(object,getdouble(value));                        }else if(fieldtype==Double.class){                            field.setDouble(object,getDouble(value));                        }                    }else {                        PropertyDescriptor proper=new PropertyDescriptor(field.getName(),object.getClass());                        Method method = proper.getWriteMethod();                        if(field.getType()==String.class){                            method.invoke(object,row.get(field.getName()));                        }else if(field.getType()==int.class){                            method.invoke(object,getInt(row.get(field.getName())));                        }else if(field.getType()==Integer.class){                            method.invoke(object,getInteger(row.get(field.getName())));                        }else if(field.getType()==double.class){                            method.invoke(object,getdouble(row.get(field.getName())));                        }else if(field.getType()==Double.class){                            method.invoke(object,getDouble(row.get(field.getName())));                        }else if(field.getType()==Date.class){                            method.invoke(object,getDates(row.get(field.getName())));                        }                        else {                           //这是解决注入问题                            PropertyEditor properEditor= PropertyEditorManager.findEditor(field.getType());                            if(properEditor!=null){                                properEditor.setAsText(row.get(field.getName()));                                method.invoke(object,properEditor.getValue());                            }else {                                System.out.println("----------------");                            }                        }                    }                }            }        }        return (T)object;    }    private static Date getDates(String s) throws ParseException {          return  DEFAULT_DATE_FORMAT.parse(s);    }    private  static Double getDouble(String value){        return Double.parseDouble(value);    }    private  static double getdouble(String value){        return Double.parseDouble(value);    }    private static int getInt(String value){         return Integer.valueOf(value);     }    private static Integer getInteger(String value){        return Integer.parseInt(value);    }    private static long getLongWropper(String value){      return Long.parseLong(value);    }    private static Long getLong(String value){        return Long.parseLong(value);    }    private static <T> List<Field> findFields(Class<T> clazz) {        Field[] aa = clazz.getDeclaredFields();        List<Field> list=new LinkedList<>();        for(Field field:aa){            list.add(field);        }        return list;    }}

test方法

package cn.itcast.shujujiegou.StructuresAnalysis;import cn.itcast.shujujiegou.Jdbc.JdbcUtils;import java.beans.IntrospectionException;import java.lang.reflect.InvocationTargetException;import java.sql.SQLException;import java.text.ParseException;import java.util.ArrayList;import java.util.Arrays;import java.util.HashMap;import java.util.List;/** * Created by likailong on 2016/9/29. */public class TestBeanMian {    public static void main(String [] args) throws InstantiationException, IllegalAccessException, NoSuchMethodException, IntrospectionException, InvocationTargetException, ParseException, SQLException {        List<HashMap<String,String>>list= Arrays.asList(                new HashMap<String, String>(){                    {                        put("name","xieyuoo");                        put("title","李凯龙");                        put("time","4");                        put("empId","123456");                        put("intnum","12");                        put("dateTime","2016-12-21 12:21:12");                    }                },                new HashMap<String, String>(){                    {                        put("name","ffff");                        put("title","标题");                        put("time","6");                        put("empId","1234567");                        put("intnum","15");                        put("dateTime","2016-12-21 12:21:12");                    }                }        );        List<UserDo> users=new ArrayList<>(list.size());        for(HashMap<String,String> row:list){            users.add(MethodBean.converMapToBean(row,UserDo.class));        }        for(UserDo userDo:users){            System.out.println(userDo.getUserName()+"--------"+userDo.getUserTitle()+"----"+userDo.getLoginTime()+"--"+userDo.getEmpId());        }       // JdbcUtils.getConnection();    }}

结果展示

展示