数据库表到Java类转换工具的实现

数据库表到Java类转换工具的实现

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目前做工作中常常用到表数据到xml的转换，常常需要将数据库表字段一一转换为Java Bean的成员，一般做法都是看着数据字段去写代码，这样效率低下还容易出错，本人深有体会，于是乎写出一个小工具自动将从数据库表到Java Bean的转换，先将核心的源码拿出来，欢迎各位博友能在更多数据库平台上实现，并分享源码。

我目前用的数据是DB2 V9。

实现的代码如下：

数据库配置文件
zfzvf.properties

host=127.0.0.1
port=50000
dbname=zfzvf
driverClassName=com.ibm.db2.jcc.DB2Driver
username=root
password=lavasoft

配置文件读取类

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.util.Properties;
import java.io.InputStream;
import java.io.IOException;

/**
* Created by IntelliJ IDEA.
* File: PropertyUtil.java
* User: leizhimin
* Date: 2008-3-5 15:13:30
*/
public class PropertyUtils {
private static final Log log = LogFactory.getLog(PropertyUtils.class);
private static String host;
private static String port;
private static String dbname;
private static String driverClassName;
private static String username;
private static String password;

private static String url;

static {
reload();
}

/**
* 私有构造方法，不需要创建对象
*/
private PropertyUtils() {
}

/**
* 重载配置文件
*
* @return 重载成功返回true，否则为false
*/
public static boolean reload() {
boolean flag = false;
Properties prop = new Properties();
InputStream in = PropertyUtils.class.getResourceAsStream("/zfzvf.properties");
try {
prop.load(in);
host = prop.getProperty("host").trim();
port = prop.getProperty("port").trim();
dbname = prop.getProperty("dbname").trim();
driverClassName = prop.getProperty("driverClassName").trim();
username = prop.getProperty("username").trim();
password = prop.getProperty("password").trim();
url = "jdbc:db2://" + host + ":" + port + "/" + dbname;
flag = true;
} catch (IOException e) {
log.error("找不系统配置文件zfzvf.properties，请检查！");
e.printStackTrace();
}
return flag;
}

public static String getDbname() {
return dbname;
}

public static void setDbname(String dbname) {
PropertyUtils.dbname = dbname;
}

public static String getDriverClassName() {
return driverClassName;
}

public static void setDriverClassName(String driverClassName) {
PropertyUtils.driverClassName = driverClassName;
}

public static String getHost() {
return host;
}

public static void setHost(String host) {
PropertyUtils.host = host;
}

public static String getPassword() {
return password;
}

public static void setPassword(String password) {
PropertyUtils.password = password;
}

public static String getPort() {
return port;
}

public static void setPort(String port) {
PropertyUtils.port = port;
}

public static String getUrl() {
return url;
}

public static void setUrl(String url) {
PropertyUtils.url = url;
}

public static String getUsername() {
return username;
}

public static void setUsername(String username) {
PropertyUtils.username = username;
}
}

核心实现类

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.sql.*;

/**
* Created by IntelliJ IDEA.
* File: DBUtils.java
* User: leizhimin
* Date: 2008-3-5 15:05:00
*/
public class DBUtils {
private static Log log = LogFactory.getLog(DBUtils.class);
private static final String tb_sql = "\n" +
"SELECT C.COLTYPE, C.NAME, C.REMARKS\n" +
" FROM SYSIBM.SYSCOLUMNS C, SYSIBM.SYSTABLES T\n" +
" WHERE C.TBNAME = T.NAME\n" +
" AND C.TBCREATOR = T.CREATOR\n" +
" AND T.CREATOR = ?\n" +
" AND T.NAME = ?";

/**
* 获取数据库连接
*
* @return 数据连接
*/
public static Connection makeConnection() {
Connection conn = null;
String url = PropertyUtils.getUrl();
String username = PropertyUtils.getUsername();
String password = PropertyUtils.getPassword();
String diverClassName = PropertyUtils.getDriverClassName();
try {
Class.forName(diverClassName);
conn = DriverManager.getConnection(url, username, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}

public static void main(String args[]) {
// testDBConnection();
getTableProperty("ZFZVF", "JG_NJQK");
}

/**
* 数据连接测试类，并将测试结果打印到控制台。
*
* @return 返回查询结果字符串
*/
public static String testDBConnection() {
Connection conn = makeConnection();
StringBuffer sb = new StringBuffer();
try {
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT NAME,CTIME FROM SYSIBM.SYSTABLES WHERE NAME NOT LIKE 'DM_%' AND NAME NOT LIKE 'SYS%'");
while (rs.next()) {
sb.append(rs.getString(1) + "\t\t\t\t" + rs.getString(2) + "\n");
}
} catch (SQLException e) {
e.printStackTrace();
}
System.out.println(sb.toString());
return sb.toString();
}

/**
* 获取表到Java Bean的成员列表的Java代码
* @param schema 模式
* @param tbName 表名
* @return Java Bean的成员列表的Java代码
*/
public static String getTableProperty(String schema, String tbName) {
Connection conn = makeConnection();
StringBuffer sb = new StringBuffer();
sb.append(schema).append(".").append(tbName).append("\n");
try {
PreparedStatement pstmt = conn.prepareStatement(tb_sql);
pstmt.setString(1, schema);
pstmt.setString(2, tbName);
ResultSet rs = pstmt.executeQuery();
while (rs.next()) {
String type = typeProcessor(rs.getString(1).trim());
String name = rs.getString(2).toLowerCase();
String remark;
if (rs.getString(3) == null) {
remark = "";
} else {
remark = rs.getString(3);
}
sb.append("\tprivate\t" + type + "\t" + name + ";\t\t\t//" + remark + "\n");
}
rs.close();
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
} finally {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
System.out.println(sb.toString());
return sb.toString();
}

/**
* SQL数据类型到Java数据类型的转换
* @param sqlType SQL数据类型
* @return Java数据类型
*/
public static String typeProcessor(String sqlType) {
String newType;
if (sqlType.equalsIgnoreCase("varchar")) newType = "String";
else if (sqlType.equalsIgnoreCase("char")) newType = "String";
else if (sqlType.equalsIgnoreCase("bigint")) newType = "Long";
else if (sqlType.equalsIgnoreCase("smallint")) newType = "int";
else if (sqlType.equalsIgnoreCase("integer")) newType = "int";
else if (sqlType.equalsIgnoreCase("decimal")) newType = "double";
else if (sqlType.equalsIgnoreCase("timestmp")) newType = "Date";
else {
newType = sqlType;
}
return newType;
}
}

运行结果：

ZFZVF.JG_NJQK
private String gxr; //管辖人
private Long bs; //标识
private Long qybs; //企业标识
private String qymc; //（企业）名称
private String zh; //字号
private String xzqh_dm; //行政区划代码
private String hylb_dm; //行业类别
private String zzxs_dm; //组织形式
private String fddbr; //法定代表人（负责人、投资人、执行合伙企业事务的合伙人）
private double zczb; //注册资本（金）
private String jydz; //经营地址
private String lxdh; //联系电话
private String jyfw; //经营范围
private String qydl_dm; //企业类型
private String qyxxlx_dm; //企业详细类型
private String yyzzhm; //营业执照号码
private String yyzxm; //经营者姓名
private Long gxdw; //管辖单位
private String zt; //状态
private Long jgbs; //机构标识
private Long zwbs; //
private Long nd; //年度
private int mjbz; //免检标志
private String njms; //年检描述
private String njwt_dm; //年检问题代码
private Long njr; //年检人
private Date njsj; //年检时间
private Date slrq; //受理日期
private Long slr; //受理人
private Date bsrq; //报送日期
private String bsr; //报送人
private int sfggdwbz; //是否广告单位标志
private int ggsfnjbz; //广告经营许可证是否年检标志
private String slyj; //受理意见
private String qylxsx_dm; //
private String njjg_dm; //
private Long shr; //
private Date shrq; //

Process finished with exit code 0

呵呵，实现很粗糙，加工一下，可以直接输出java Bean的源码。

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