import org.apache.commons.lang3.time.DateFormatUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSetMetaData;
import java.util.Date;
public class GenerateEntityMySql {
private static final Logger LOGGER = LoggerFactory.getLogger(GenerateEntityMySql.class);
private String packageOutPath = "com.user.entity";//指定实体生成所在包的路径
private String authorName = "test";//作者名字
private String tablename = "t_user";//表名
private String[] colnames; // 列名数组
private String[] colTypes; //列名类型数组
private int[] colSizes; //列名大小数组
private boolean f_util = false; // 是否需要导入包java.util.*
private boolean f_sql = false; // 是否需要导入包java.sql.*
//数据库连接
private static final String URL = "jdbc:mysql://localhost:3306/test555";
private static final String NAME = "root";
private static final String PASS = "root";
private static final String DRIVER = "com.mysql.jdbc.Driver";
/**
* 使用默认构造方法来构造实体类
*/
public GenerateEntityMySql() {
//生成实体的表明
String sql = "select * from " + tablename;
try (
Connection con = DriverManager.getConnection(URL, NAME, PASS);
PreparedStatement pStemt = con.prepareStatement(sql)
) {
try {
Class.forName(DRIVER);
} catch (ClassNotFoundException e1) {
e1.printStackTrace();
}
ResultSetMetaData rsmd = pStemt.getMetaData();
int size = rsmd.getColumnCount(); //统计列
colnames = new String[size];
colTypes = new String[size];
colSizes = new int[size];
for (int i = 0; i < size; i++) {
colnames[i] = rsmd.getColumnName(i + 1);
colTypes[i] = rsmd.getColumnTypeName(i + 1);
if (colTypes[i].equalsIgnoreCase("datetime")) {
f_util = true;
}
if (colTypes[i].equalsIgnoreCase("image") || colTypes[i].equalsIgnoreCase("text")) {
f_sql = true;
}
colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
}
String content = parse(colnames, colTypes, colSizes);
LOGGER.info(content);
File directory = new File("");//需要填写工程名
//System.out.println("绝对路径:"+directory.getAbsolutePath());
//System.out.println("相对路径:"+directory.getCanonicalPath());
String path = this.getClass().getResource("").getPath();
String outputPath1 = directory.getAbsolutePath() + "/src/" + path.substring(path.lastIndexOf("/com/", path.length()), path.length()) + initcap(tablename) + ".java";
System.out.println(outputPath1);
String outputPath = directory.getAbsolutePath() + "/src/main/java/" + this.packageOutPath.replace(".", "/") + "/" + initcap(tablename) + ".java";
FileWriter fw = new FileWriter(outputPath);
PrintWriter pw = new PrintWriter(fw);
pw.println(content);
pw.flush();
pw.close();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 功能:生成实体类主体代码
*
* @param colnames
* @param colTypes
* @param colSizes
* @return
*/
private String parse(String[] colnames, String[] colTypes, int[] colSizes) {
StringBuffer sb = new StringBuffer();
//判断是否导入工具包
if (f_util) {
sb.append("import java.util.Date;\r\n");
}
if (f_sql) {
sb.append("import java.sql.*;\r\n");
}
//包名,必须要先创建包名
sb.append("package " + this.packageOutPath + ";\r\n");
sb.append("\r\n");
//注释部分
sb.append(" /**\r\n");
sb.append(" * " + tablename + " 实体类\r\n");
sb.append(" * Created by " + this.authorName + "" + DateFormatUtils.format(new Date(), "yyyy-MM-dd") + "\r\n");
sb.append(" */ \r\n");
//实体部分
sb.append("\r\n\r\npublic class " + initcap(tablename) + "{\r\n");
processAllAttrs(sb);//属性
processAllMethod(sb);//get set方法
sb.append("}\r\n");
LOGGER.info(sb.toString());
return sb.toString();
}
/**
* 功能:生成所有属性
*
* @param sb
*/
private void processAllAttrs(StringBuffer sb) {
for (int i = 0; i < colnames.length; i++) {
sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + colnames[i] + ";\r\n");
}
}
/**
* 功能:生成所有方法
*
* @param sb
*/
private void processAllMethod(StringBuffer sb) {
for (int i = 0; i < colnames.length; i++) {
sb.append("\tpublic void set" + initcap(colnames[i]) + "(" + sqlType2JavaType(colTypes[i]) + " " +
colnames[i] + "){\r\n");
sb.append("\tthis." + colnames[i] + "=" + colnames[i] + ";\r\n");
sb.append("\t}\r\n");
sb.append("\tpublic " + sqlType2JavaType(colTypes[i]) + " get" + initcap(colnames[i]) + "(){\r\n");
sb.append("\t\treturn " + colnames[i] + ";\r\n");
sb.append("\t}\r\n");
}
}
/**
* 功能:将输入字符串的首字母改成大写
*
* @param str
* @return
*/
private String initcap(String str) {
char[] ch = str.toCharArray();
if (ch[0] >= 'a' && ch[0] <= 'z') {
ch[0] = (char) (ch[0] - 32);
}
return new String(ch);
}
/**
* 功能:获得列的数据类型
*
* @param sqlType
* @return
*/
private String sqlType2JavaType(String sqlType) {
if (sqlType.equalsIgnoreCase("bit")) {
return "boolean";
} else if (sqlType.equalsIgnoreCase("tinyint")) {
return "byte";
} else if (sqlType.equalsIgnoreCase("smallint")) {
return "short";
} else if (sqlType.equalsIgnoreCase("int")) {
return "int";
} else if (sqlType.equalsIgnoreCase("bigint")) {
return "long";
} else if (sqlType.equalsIgnoreCase("float")) {
return "float";
} else if (sqlType.equalsIgnoreCase("decimal") || sqlType.equalsIgnoreCase("numeric")
|| sqlType.equalsIgnoreCase("real") || sqlType.equalsIgnoreCase("money")
|| sqlType.equalsIgnoreCase("smallmoney")) {
return "double";
} else if (sqlType.equalsIgnoreCase("varchar") || sqlType.equalsIgnoreCase("char")
|| sqlType.equalsIgnoreCase("nvarchar") || sqlType.equalsIgnoreCase("nchar")
|| sqlType.equalsIgnoreCase("text")) {
return "String";
} else if (sqlType.equalsIgnoreCase("datetime")) {
return "Date";
} else if (sqlType.equalsIgnoreCase("image")) {
return "Blod";
}
return null;
}
/**
* 出口
* TODO
*
* @param args
*/
public static void main(String[] args) {
new GenerateEntityMySql();
}
}
通过反射把数据库表生成实体类
最新推荐文章于 2025-06-19 12:56:43 发布
