java读取数据库指定表，生成bean，获取主键，自动生成get、set方法

开发一个程序涉及很多数据库表，之前介绍过用

EXCEL通过VBA生成SQL，自动生成创建表结构SQL

在使用mvc架构开发要将数据库表变成bean,这也是个重复性无技术含量的工作，为了打发无聊编写一个小工具，自动读取数据库并生成bean，同时生成get、set方法。

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class BeanUtil {
private static final String TABLE_NAME = "TABLE_NAME";
private static final String COLUMN_NAME = "COLUMN_NAME";
private static final String DATA_TYPE = "DATA_TYPE";
private static final String DATA_SCALE = "DATA_SCALE";
private static final String ISPK = "ISPK";
private static final String COMMENTS = "COMMENTS";

public static void main(String[] args) {
BeanUtil beanUtil = new BeanUtil();
beanUtil.createBean("tablename","beanname","com.test.bean","E:\\trunk\\Sources\\trust\\com\\test\\bean\\");//填写表名，bean名，bean存放路径

}

@SuppressWarnings({ "rawtypes", "unchecked" })
private void createBean(String tableName,String className,String packageName,String path){
StringBuffer result = new StringBuffer();
StringBuffer getsetresult = new StringBuffer();
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl", "hstdc", "tdc");
Statement stat = conn.createStatement();
StringBuffer sql = new StringBuffer();
sql.append(" select                                            ")
.append(" cols.TABLE_NAME,                                   ")
.append(" cols.COLUMN_NAME,                                  ")
.append(" cols.DATA_TYPE,                                    ")
.append(" cols.DATA_SCALE,                                   ")
.append(" com.COMMENTS,                                      ")
.append(" case when cc.column_name=cols.COLUMN_NAME then 1   ")
.append("   else 0 end ISPK                                  ")
.append(" from                                               ")
.append(" user_tab_cols cols,                                ")
.append(" user_constraints ct,                               ")
.append(" user_cons_columns cc,                              ")
.append(" user_col_comments com                              ")
.append(" where cols.TABLE_NAME = ct.table_name(+)           ")
.append(" and cols.TABLE_NAME = com.table_name(+)            ")
.append(" and cols.COLUMN_NAME = com.column_name(+)          ")
.append(" and ct.constraint_name =  cc.constraint_name       ")
.append(" and ct.constraint_type='P'                         ")
.append(" and ct.TABLE_NAME='")
.append(tableName)
.append("'");

ResultSet rs = stat.executeQuery(sql.toString());
List<Map> ls = new ArrayList<Map>();
while(rs.next()){
Map map = new HashMap<String,Object>();
String columnName = rs.getString(BeanUtil.COLUMN_NAME);
String dataType = rs.getString(BeanUtil.DATA_TYPE);
Integer dataScale = rs.getInt(BeanUtil.DATA_SCALE);
Boolean isPK = rs.getBoolean(BeanUtil.ISPK);
String comments = rs.getString(BeanUtil.COMMENTS);
map.put(BeanUtil.TABLE_NAME, tableName);
map.put(BeanUtil.COLUMN_NAME, columnName);
map.put(BeanUtil.DATA_TYPE, dataType);
map.put(BeanUtil.DATA_SCALE, dataScale);
map.put(BeanUtil.ISPK, isPK);
map.put(BeanUtil.COMMENTS, comments);

ls.add(map);
}

result.append("package ").append(packageName).append(";\n");
result.append("import java.io.Serializable;\n");
result.append("import javax.persistence.Column;\n");
result.append("import javax.persistence.Entity;\n");
result.append("import javax.persistence.Id;\n");
result.append("import javax.persistence.Table;\n");
result.append("//Auto-Generated by com.common.uitl.BeanUtil \n");
result.append("@Entity\n")
.append("@Table(name=\"" + tableName + "\")\n")
.append("public class " + className + " implements Serializable{\n");

for(int i=0; i<ls.size(); i++){
Map map = ls.get(i);

String columnName = (String)map.get(BeanUtil.COLUMN_NAME);

String varName = columnName.toLowerCase().substring(2);//截取两位之后的，由于字段命名柜子是类型加下划线，如：L_NO,C_NAME
String getsetName=varName.replaceFirst(varName.substring(0, 1),varName.substring(0, 1).toUpperCase());

String comments = (String)map.get(BeanUtil.COMMENTS);
if(comments==null || comments.equals("")) comments = "无";

String dataType = (String)map.get(BeanUtil.DATA_TYPE);
Integer dataScale = (Integer)map.get(BeanUtil.DATA_SCALE);
Boolean isPK = (Boolean)map.get(BeanUtil.ISPK);

//System.out.println(dataType);
String varType = null;
if(dataType.equals("DATE")){
varType = "Date";
}else if(dataType.equals("NUMBER") && dataScale > 0){
varType = "Double";
}else if(dataType.equals("NUMBER")){
varType = "Integer";
}else{
varType = "String";
}

if(isPK){

result.append("\t @Id\n");
}

result.append("\t @Column(name=\"" + columnName + "\")" + "\n")
.append("\t private  " + varType + "  " + varName + ";" + "\t\t //" + comments + "\n\n");
getsetresult.append("\t public " + varType + " " + "get"+getsetName +"(){\n")
.append("\t\t return "+varName+";"+"\n")
.append("\t } \n\n")
.append("\t public void " + "set"+getsetName +"("+varType + " " + varName +"){"+"\n")
.append("\t\t"+"this."+varName+"="+varName+";"+"\n")
.append("\t } \n\n");
}

result.append(getsetresult).append("}");

File file = new File(path + className + ".java");
BufferedWriter bw = new BufferedWriter(new FileWriter(file));
bw.write(result.toString());
bw.flush();
bw.close();

}catch(Exception e){
e.printStackTrace();
}
}
}

结果示例：

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="TEST")
public class Tset implements Serializable{

@Id
@Column(name="C_MESTYPE")
private  String  mestype;		 //报文类型

@Column(name="C_MESTYPE_NAME")
private  String  mestype_name;		 //类型名称

@Column(name="C_CONTENT")
private  String  content;		 //报文内容

public String getMestype(){
return mestype;
}

public void setMestype(String mestype){
this.mestype=mestype;
}

public String getMestype_name(){
return mestype_name;
}

public void setMestype_name(String mestype_name){
this.mestype_name=mestype_name;
}

public String getContent(){
return content;
}

public void setContent(String content){
this.content=content;
}

}