具体代码如下：
package param;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
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.util.ArrayList;
import java.util.List;
public class AutoCreateBean {
// mysql 驱动类
private static final String DRIVER = "com.mysql.jdbc.Driver";
// 数据库登录用户名
private static final String USER = "root";
// 数据库登录密码
private static final String PASSWORD = "123456";
// 数据库连接地址
private static final String URL = "jdbc:mysql://localhost:3306/ssm";
private static String tablename;
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.*
/**
* 获取指定数据库中包含的表 TBlist
*
* @packageName com.util
* @return 返回所有表名(将表名放到一个集合中)
* @throws Exception
*/
public List TBlist() throws Exception {
// 访问数据库 采用 JDBC方式
Class.forName(DRIVER);
Connection con = DriverManager.getConnection(URL, USER, PASSWORD);
DatabaseMetaData md = con.getMetaData();
List list = null;
ResultSet rs = md.getTables(null, null, null, null);
if (rs != null) {
list = new ArrayList();
}
while (rs.next()) {
/*
* 设置表名
*/
String tableName = rs.getString("TABLE_NAME");
list.add(tableName);
}
rs = null;
md = null;
con = null;
return list;
}
public void GenEntity(List TBlist, String packageName)throws Exception {
Connection conn = null;
PreparedStatement pstmt = null;
ResultSetMetaData rsmd = null;
// 访问数据库 采用 JDBC方式
Class.forName(DRIVER);
conn = DriverManager.getConnection(URL, USER, PASSWORD);
for (int k = 0; k < TBlist.size(); k++) {
tablename = TBlist.get(k);
String strsql = "select * from " + tablename;
pstmt = conn.prepareStatement(strsql);
rsmd = pstmt.getMetaData();
int size = rsmd.getColumnCount();
// 共有多少列
colnames = new String[size];
colTypes = new String[size];
colSizes = new int[size];
for (int i = 0; i < rsmd.getColumnCount(); 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);
}
markerBean(initcap(tablename), parse(), packageName);
}
pstmt = null;
rsmd = null;
conn = null;
}
/**
* 解析处理(生成实体类主体代码)
*/
private String parse() {
StringBuffer sb = new StringBuffer();
if (f_util) {
sb.append("import java.util.Date;\r\n");
}
if (f_sql) {
sb.append("import java.sql.*;\r\n\r\n\r\n");
}
sb.append("public class " + initcap(tablename) + " {\r\n");
processAllAttrs(sb);
processAllMethod(sb);
sb.append("}\r\n");
return sb.toString();
}
/**
* 创建java 文件 将生成的属性 get/set 方法 保存到 文件中 markerBean
*
* @packageName fanshe
* @param className
* 类名称
* @param content
* 类内容 包括属性 getset 方法
*/
public void markerBean(String className, String content, String packageName) {
String folder = System.getProperty("user.dir") + "/src/" + packageName + "/";
File file = new File(folder);
if (!file.exists()) {
file.mkdirs();
}
String fileName = folder + className + ".java";
try {
File newdao = new File(fileName);
FileWriter fw = new FileWriter(newdao);
fw.write("package\t" + packageName.replace("/", ".") + ";\r\n");
fw.write(content);
fw.flush();
fw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 生成所有的方法
*
* @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("\t\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");
}
}
/**
* 解析输出属性
*
* @return
*/
private void processAllAttrs(StringBuffer sb) {
for (int i = 0; i < colnames.length; i++) {
sb.append("\tprivate " + sqlType2JavaType(colTypes[i]) + " " + colnames[i] + ";\r\n");
}
}
/**
* 把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);
}
private String sqlType2JavaType(String sqlType) {
if (sqlType.equalsIgnoreCase("bit")) {
return "bool";
} 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")) {
return "double";
} else if (sqlType.equalsIgnoreCase("money")
|| sqlType.equalsIgnoreCase("smallmoney")) {
return "double";
} else if (sqlType.equalsIgnoreCase("varchar")
|| sqlType.equalsIgnoreCase("char")
|| sqlType.equalsIgnoreCase("nvarchar")
|| sqlType.equalsIgnoreCase("nchar")) {
return "String";
} else if (sqlType.equalsIgnoreCase("datetime")
||sqlType.equalsIgnoreCase("date")){
return "Date";
}
else if (sqlType.equalsIgnoreCase("image")) {
return "Blob";
} else if (sqlType.equalsIgnoreCase("text")) {
return "Clob";
}
return null;
}
public static void main(String[] args) throws Exception {
AutoCreateBean auto = new AutoCreateBean();
List list = auto.TBlist();
auto.GenEntity(list, "bean");
System.out.println("成功!");
}
}
在此处的"bean"对应的是项目下的bean包，如下所示:
数据库里有多少张表就会创建多少张javaBean。最后结果如下：
特别在此声明，期间可能遇到错误，所以可以用下面的类来进行测试是否连接成功：
package param;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class ConnectToDataBase {
public static Connection getDataBaseConnection(){
String driver="com.mysql.jdbc.Driver";
String url="jdbc:mysql://localhost:3306/ssm";
String user="root";
String password="123456";
//加载驱动程序
try {
Class.forName(driver);
//System.out.println("驱动程序加载成功");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
//链接数据库
Connection conn=null;
try {
conn=DriverManager.getConnection(url, user, password);
if (!conn.isClosed()) {
System.out.println("连接数据库成功");
}
} catch (SQLException e) {
System.out.println("链接数据库失败: "+e.getMessage());
}
return conn;
}
public static void main(String[] args) {
getDataBaseConnection();
}
}
