utils/GenEntityMysql.java
package utils;
import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.text.SimpleDateFormat;
import java.util.Date;
public class GenEntityMysql {
private static final GenEntityMysql INSTANCE = new GenEntityMysql();
private String tableName; // 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 needUtil = false; // 是否需要导入包java.util.*
private boolean needSql = false; // 是否需要导入包java.sql.*
private static final SimpleDateFormat SDF = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
private static final String SQL = "SELECT * FROM "; // 数据库操作
// TODO 需要修改的地方
private static final String URL = "jdbc:mysql://127.0.0.1:3306/yxyk-golo";
private static final String NAME = "root";
private static final String PASS = "123456";
private static final String DRIVER = "com.mysql.jdbc.Driver";
private String packagePath = "com.yxyk.golo.entity"; // 实体包名
private String packageOutPath = "main/java/com/yxyk/golo/entity"; // 实体生成(src目录)路径
private String authorName = "php-note.com"; // 作者名字
/**
* 类的构造方法
*/
private GenEntityMysql() {
}
/**
* 生成class的所有内容
*/
private String parse() {
StringBuffer sb = new StringBuffer();
sb.append("package " + packagePath + ";\r\n");
sb.append("\r\n");
// 判断是否导入工具包
if (needUtil) {
sb.append("import java.util.Date;\r\n");
}
if (needSql) {
sb.append("import java.sql.*;\r\n");
}
// 注释部分
sb.append("\r\n/**\r\n");
sb.append(" * 表名： " + tableName + "\r\n");
sb.append(" * \r\n");
sb.append(" * @author " + authorName + "\r\n");
sb.append(" * @since " + SDF.format(new Date()) + "\r\n");
sb.append(" */ \r\n");
// 实体部分
sb.append("public class " + getTransStr(tableName, true) + " {\r\n");
processAllAttrs(sb); // 属性
processAllMethod(sb); // get set方法
sb.append("}");
return sb.toString();
}
/**
* 生成所有成员变量
*/
private void processAllAttrs(StringBuffer sb) {
for (int i = 0; i < colNames.length; i++) {
sb.append(" private " + sqlType2JavaType(colTypes[i]) + " " + getTransStr(colNames[i], false) + ";\r\n");
}
}
/**
* 生成所有get/set方法
*/
private void processAllMethod(StringBuffer sb) {
for (int i = 0; i < colNames.length; i++) {
sb.append("\r\n public void set" + getTransStr(colNames[i], true) + "(" + sqlType2JavaType(colTypes[i]) + " "
+ getTransStr(colNames[i], false) + ") {\r\n");
sb.append(" this." + getTransStr(colNames[i], false) + " = " + getTransStr(colNames[i], false) + ";\r\n");
sb.append(" }\r\n\r\n");
sb.append(" public " + sqlType2JavaType(colTypes[i]) + " get" + getTransStr(colNames[i], true) + "() {\r\n");
sb.append(" return " + getTransStr(colNames[i], false) + ";\r\n");
sb.append(" }\r\n");
}
}
/**
* 将传入字符串的首字母转成大写
*/
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);
}
/**
* 将mysql中表名和字段名转换成驼峰形式
*/
private String getTransStr(String before, boolean firstChar2Upper) {
// 不带"_"的字符串,则直接首字母大写后返回
if (!before.contains("_"))
return firstChar2Upper ? initCap(before) : before;
String[] strs = before.split("_");
StringBuffer after = null;
if (firstChar2Upper) {
after = new StringBuffer(initCap(strs[0]));
} else {
after = new StringBuffer(strs[0]);
}
for (int i=1; i<strs.length; i++)
after.append(initCap(strs[i]));
return after.toString();
}
/**
* 查找sql字段类型所对应的Java类型
*/
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") || sqlType.equalsIgnoreCase("INTEGER")) {
return "Integer";
} 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")||sqlType.equalsIgnoreCase("timestamp")) {
return "Date";
} else if (sqlType.equalsIgnoreCase("image")) {
return "Blod";
}
return null;
}
/**
* 生成方法
*/
private void generate() throws Exception {
// 与数据库的连接
Connection con;
PreparedStatement pStemt = null;
Class.forName(DRIVER);
con = DriverManager.getConnection(URL, NAME, PASS);
System.out.println("connect database success...");
// 获取数据库的元数据
DatabaseMetaData db = con.getMetaData();
// 从元数据中获取到所有的表名
ResultSet rs = db.getTables(null, null, null, new String[] { "TABLE" });
String tableSql;
PrintWriter pw = null;
while (rs.next()) {
tableName = rs.getString(3);
tableSql = SQL + tableName;
pStemt = con.prepareStatement(tableSql);
ResultSetMetaData rsmd = pStemt.getMetaData();
int size = rsmd.getColumnCount();
colNames = new String[size];
colTypes = new String[size];
colSizes = new int[size];
// 获取所需的信息
for (int i = 0; i < size; i++) {
colNames[i] = rsmd.getColumnName(i + 1);
colTypes[i] = rsmd.getColumnTypeName(i + 1);
if (colTypes[i].equalsIgnoreCase("datetime")) {
needUtil = true;
}
if (colTypes[i].equalsIgnoreCase("image") || colTypes[i].equalsIgnoreCase("text")) {
needSql = true;
}
colSizes[i] = rsmd.getColumnDisplaySize(i + 1);
}
// 解析生成class的所有内容
String content = parse();
// 输出生成文件
File directory = new File("");
String outputPath = directory.getAbsolutePath() + "/src/" + packageOutPath
+ "/" + getTransStr(tableName, true) + ".java";
FileWriter fw = new FileWriter(outputPath);
pw = new PrintWriter(fw);
pw.println(content);
pw.flush();
System.out.println("create class >>>>> " + tableName);
}
if (pw != null)
pw.close();
}
/**
* 执行方法
*/
public static void main(String[] args) {
try {
INSTANCE.generate();
System.out.println("generate classes success!");
} catch (Exception e) {
e.printStackTrace();
}
}
}