mybatis根据实体类产生mapper文件

来源：互联网发布：bf风森系部落卫衣淘宝编辑：程序博客网时间：2024/06/05 09:18

主要思路是根据po上的注解来生成相应的mapper文件，并输出在控制台上。

解析类：

package com.video.util;

import java.lang.reflect.Field;
import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.ResourceBundle;
import com.video.annotation.Column;
import com.video.annotation.ID;
import com.video.annotation.Table;

public class GeneratorUtil {

   private static final ResourceBundle generatorBundle = ResourceBundle
           .getBundle("generator");

   private static final String START_KEY = "start";

   private static final String END_KEY = "end";

   private static final String INSERT_STATEMENT = "insert";

   private static final String SEARCH_VO_STATEMENT = "selectVoBySo";

   private static final String SEARCH_PO_STATEMENT = "selectPoBySo";

   private static final String UPDATE_STATEMENT = "update";

   private static final String DELETE_STATEMENT = "delete";

   private static String tableName;

   private static Map<String, String> propertyToColumnMap;

   private static final String DECIMAL_SPLIT = ":";

   public static void main(String[] args) {

       String targetClassName = "com.video.domain.User";

       init(targetClassName);

       StringBuffer buffer = new StringBuffer();

       buffer.append(generatorStart(targetClassName));

       buffer.append(generatorSearchPoBySo(targetClassName));

       buffer.append(generatorInsert(targetClassName));

       buffer.append(generatorUpdate(targetClassName));

       buffer.append(generatorEnd(targetClassName));

       System.out.println(buffer.toString());

   }

   private static void init(String targetClassName) {

       Class clazz = loadClassByName(targetClassName);

       Table tableAno = (Table) clazz.getAnnotation(Table.class);

       tableName = tableAno.name();

       propertyToColumnMap = new HashMap<String, String>();

       Field[] fields = clazz.getDeclaredFields();

       for (Field field : fields) {
           if (field.isAnnotationPresent(ID.class)) {
               ID id = field.getAnnotation(ID.class);
               try {
                   propertyToColumnMap.put(field.getName() + DECIMAL_SPLIT
                           + field.getType().getName(), id.name());
               } catch (Exception e) {
                   e.printStackTrace();
               }
           } else if (field.isAnnotationPresent(Column.class)) {
               Column column = field.getAnnotation(Column.class);
               propertyToColumnMap.put(field.getName() + DECIMAL_SPLIT
                       + field.getType().getName(), column.name());
           }
       }
   }

   private static String generatorStart(String targetClassName) {
       String start = generatorBundle.getString(START_KEY);
       return MessageFormat.format(start, new Object[] { targetClassName })
               + "\n\n";
   }

   private static String generatorEnd(String targetClassName) {
       String end = generatorBundle.getString(END_KEY);
       return MessageFormat.format(end, new Object[] {}) + "\n";
   }

   private static String generatorSearchPoBySo(String targetClassName) {
       String src = generatorBundle.getString("select");
       return MessageFormat.format(src, new Object[] { SEARCH_PO_STATEMENT,
               targetClassName, tableName })
               + "\n";
   }

   private static String generatorSearchVoBySo(String targetClassName) {
       String src = generatorBundle.getString("select");
       return MessageFormat.format(src, new Object[] { SEARCH_VO_STATEMENT,
               targetClassName, tableName })
               + "\n";
   }

   private static String generatorInsert(String targetClassName) {
       String src = generatorBundle.getString(INSERT_STATEMENT);
       StringBuffer columnContent = new StringBuffer();

       StringBuffer valuesContent = new StringBuffer();
       int count = 0;
       for (Entry<String, String> entry : propertyToColumnMap.entrySet()) {
           if (count > 0) {
               columnContent.append(",");
               valuesContent.append(",");
           }
           columnContent.append(entry.getValue());

           String[] keys = entry.getKey().split("\\" + DECIMAL_SPLIT);
           valuesContent.append("#{" + keys[0] + ",");
           valuesContent.append(getStringByType(keys[1]));
           valuesContent.append("}");
           count++;
       }

       return MessageFormat.format(src, new Object[] { targetClassName,
               tableName, columnContent.toString(),valuesContent.toString() })
               + "\n";
   }

   private static String getStringByType(String type){
       String res=null;
       if (Long.class.getName().equals(type)) {
           res="jdbcType=BIGINT";
       } else if (String.class.getName().equals(type)) {
           res="jdbcType=VARCHAR";
       } else {
           throw new RuntimeException("不支持的属性类型：" + type);
       }
       return res;
   }

   private static String generatorUpdate(String targetClassName) {
       String src = generatorBundle.getString(UPDATE_STATEMENT);
       StringBuffer content = new StringBuffer();

       int count=0;
       for(Entry<String, String> entity:propertyToColumnMap.entrySet()){
           if(count>0){
               content.append(",");
           }

           String[] keys=entity.getKey().split("\\"+DECIMAL_SPLIT);
           content.append(entity.getValue()+"=#{"+keys[0]+",");
           content.append(getStringByType(keys[1])+"}");

           count++;
       }

       return MessageFormat.format(src, new Object[] { targetClassName,
               tableName, content.toString()})
               + "\n";
   }

   public static Class loadClassByName(String targetClassName) {
       ClassLoader cl = Thread.currentThread().getContextClassLoader();
       try {
           Class target = cl.loadClass(targetClassName);
           return target;
       } catch (ClassNotFoundException e) {
           e.printStackTrace();
       }
       return null;
   }

}

0 1