使用JDBC获取各数据库的Meta信息——表以及对应的列-阿里云开发者社区

先贴代码,作为草稿:

第一个是工具类, MapUtil.java

[java] view plain copy

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* map转换工具
*/
public class MapUtil {
/**
* 将List中的Key转换为小写
* @param list 返回新对象
* @return
*/
public static List<Map<String, Object>> convertKeyList2LowerCase(List<Map<String, Object>> list){
if(null==list) {
return null;
}
List<Map<String, Object>> resultList = new ArrayList<Map<String,Object>>();
//
Iterator<Map<String, Object>> iteratorL = list.iterator();
while (iteratorL.hasNext()) {
Map<String, Object> map = (Map<String, Object>) iteratorL.next();
//
Map<String, Object> result = convertKey2LowerCase(map);
if(null != result){
resultList.add(result);
}
}
//
return resultList;
}
/**
* 转换单个map,将key转换为小写.
* @param map 返回新对象
* @return
*/
public static Map<String, Object> convertKey2LowerCase(Map<String, Object> map){
if(null==map) {
return null;
}
Map<String, Object> result = new HashMap<String, Object>();
//
Set<String> keys = map.keySet();
//
Iterator<String> iteratorK = keys.iterator();
while (iteratorK.hasNext()) {
String key = (String) iteratorK.next();
Object value = map.get(key);
if(null == key){
continue;
}
//
String keyL = key.toLowerCase();
result.put(keyL, value);
}
return result;
}
/**
* 将List中Map的Key转换为小写.
* @param list
* @return
*/
public static List<Map<String, Object>> trimListKeyValue(List<Map<String, Object>> list){
if(null==list) {
return null;
}
List<Map<String, Object>> resultList = new ArrayList<Map<String,Object>>();
//
Iterator<Map<String, Object>> iteratorL = list.iterator();
while (iteratorL.hasNext()) {
Map<String, Object> map = (Map<String, Object>) iteratorL.next();
//
Map<String, Object> result = trimKeyValue(map);
if(null != result){
resultList.add(result);
}
}
//
return resultList;
}
/**
* 转换单个map,将key转换为小写.
* @param map 返回新对象
* @return
*/
public static Map<String, Object> trimKeyValue(Map<String, Object> map){
if(null==map) {
return null;
}
Map<String, Object> result = new HashMap<String, Object>();
//
Set<String> keys = map.keySet();
//
Iterator<String> iteratorK = keys.iterator();
while (iteratorK.hasNext()) {
String key = (String) iteratorK.next();
Object value = map.get(key);
if(null == key){
continue;
}
//
String keyT = key.trim();
if(value instanceof String){
String valueT = String.valueOf(value).trim();
result.put(keyT, valueT);
} else {
result.put(keyT, value);
}
}
return result;
}
}

然后是具体的实现工具类,使用了阿里巴巴的 fastjson 工具包；里面的测试类可以忽略

[java] view plain copy

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import com.alibaba.fastjson.JSONArray;
/**
* 需要注意,想要有表字段描述信息，获取连接时需要指定某些特殊属性<br/>
* 数据交换-工具类
*/
public class DBMSMetaUtil {
/**
* 数据库类型,枚举
*
*/
public static enum DATABASETYPE {
ORACLE, MYSQL, SQLSERVER, SQLSERVER2005, DB2, INFORMIX, SYBASE, OTHER, EMPTY
}
/**
* 根据字符串,判断数据库类型
*
* @param databasetype
* @return
*/
public static DATABASETYPE parseDATABASETYPE(String databasetype) {
// 空类型
if (null == databasetype || databasetype.trim().length() < 1) {
return DATABASETYPE.EMPTY;
}
// 截断首尾空格,转换为大写
databasetype = databasetype.trim().toUpperCase();
// Oracle数据库
if (databasetype.contains("ORACLE")) {
//
return DATABASETYPE.ORACLE;
}
// MYSQL 数据库
if (databasetype.contains("MYSQL")) {
//
return DATABASETYPE.MYSQL;
}
// SQL SERVER 数据库
if (databasetype.contains("SQL") && databasetype.contains("SERVER")) {
//
if (databasetype.contains("2005") || databasetype.contains("2008") || databasetype.contains("2012")) {
try {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return DATABASETYPE.SQLSERVER2005;
} else {
try {
// 注册 JTDS
Class.forName("net.sourceforge.jtds.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return DATABASETYPE.SQLSERVER;
}
}
// 下面的这几个没有经过实践测试, 判断可能不准确
// DB2 数据库
if (databasetype.contains("DB2")) {
//
return DATABASETYPE.DB2;
}
// INFORMIX 数据库
if (databasetype.contains("INFORMIX")) {
//
return DATABASETYPE.INFORMIX;
}
// SYBASE 数据库
if (databasetype.contains("SYBASE")) {
//
return DATABASETYPE.SYBASE;
}
// 默认,返回其他
return DATABASETYPE.OTHER;
}
/**
* 列出数据库的所有表
*/
// 可以参考: http://www.cnblogs.com/chinafine/articles/1847205.html
public static List<Map<String, Object>> listTables(String databasetype, String ip, String port, String dbname,
String username, String password) {
// 去除首尾空格
databasetype = trim(databasetype);
ip = trim(ip);
port = trim(port);
dbname = trim(dbname);
username = trim(username);
password = trim(password);
//
DATABASETYPE dbtype = parseDATABASETYPE(databasetype);
//
List<Map<String, Object>> result = null;
String url = concatDBURL(dbtype, ip, port, dbname);
Connection conn = getConnection(url, username, password);
// Statement stmt = null;
ResultSet rs = null;
//
try {
// 这句话我也不懂是什么意思... 好像没什么用
conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);
// 获取Meta信息对象
DatabaseMetaData meta = conn.getMetaData();
// 数据库
String catalog = null;
// 数据库的用户
String schemaPattern = null;// meta.getUserName();
// 表名
String tableNamePattern = null;//
// types指的是table、view
String[] types = { "TABLE" };
// Oracle
if (DATABASETYPE.ORACLE.equals(dbtype)) {
schemaPattern = username;
if (null != schemaPattern) {
schemaPattern = schemaPattern.toUpperCase();
}
// 查询
rs = meta.getTables(catalog, schemaPattern, tableNamePattern, types);
} else if (DATABASETYPE.MYSQL.equals(dbtype)) {
// Mysql查询
// MySQL 的 table 这一级别查询不到备注信息
schemaPattern = dbname;
rs = meta.getTables(catalog, schemaPattern, tableNamePattern, types);
} else if (DATABASETYPE.SQLSERVER.equals(dbtype) || DATABASETYPE.SQLSERVER2005.equals(dbtype)) {
// SqlServer
tableNamePattern = "%";
rs = meta.getTables(catalog, schemaPattern, tableNamePattern, types);
} else if (DATABASETYPE.DB2.equals(dbtype)) {
// DB2查询
schemaPattern = "jence_user";
tableNamePattern = "%";
rs = meta.getTables(catalog, schemaPattern, tableNamePattern, types);
} else if (DATABASETYPE.INFORMIX.equals(dbtype)) {
// SqlServer
tableNamePattern = "%";
rs = meta.getTables(catalog, schemaPattern, tableNamePattern, types);
} else if (DATABASETYPE.SYBASE.equals(dbtype)) {
// SqlServer
tableNamePattern = "%";
rs = meta.getTables(catalog, schemaPattern, tableNamePattern, types);
} else {
throw new RuntimeException("不认识的数据库类型!");
}
//
result = parseResultSetToMapList(rs);
} catch (Exception e) {
e.printStackTrace();
} finally {
close(rs);
close(conn);
}
//
return result;
}
/**
* 列出表的所有字段
*/
public static List<Map<String, Object>> listColumns(String databasetype, String ip, String port, String dbname,
String username, String password, String tableName) {
// 去除首尾空格
databasetype = trim(databasetype);
ip = trim(ip);
port = trim(port);
dbname = trim(dbname);
username = trim(username);
password = trim(password);
tableName = trim(tableName);
//
DATABASETYPE dbtype = parseDATABASETYPE(databasetype);
//
List<Map<String, Object>> result = null;
String url = concatDBURL(dbtype, ip, port, dbname);
Connection conn = getConnection(url, username, password);
// Statement stmt = null;
ResultSet rs = null;
//
try {
// 获取Meta信息对象
DatabaseMetaData meta = conn.getMetaData();
// 数据库
String catalog = null;
// 数据库的用户
String schemaPattern = null;// meta.getUserName();
// 表名
String tableNamePattern = tableName;//
// 转换为大写
if (null != tableNamePattern) {
tableNamePattern = tableNamePattern.toUpperCase();
}
//
String columnNamePattern = null;
// Oracle
if (DATABASETYPE.ORACLE.equals(dbtype)) {
// 查询
schemaPattern = username;
if (null != schemaPattern) {
schemaPattern = schemaPattern.toUpperCase();
}
} else {
//
}
rs = meta.getColumns(catalog, schemaPattern, tableNamePattern, columnNamePattern);
// TODO 获取主键列,但还没使用
meta.getPrimaryKeys(catalog, schemaPattern, tableNamePattern);
//
result = parseResultSetToMapList(rs);
} catch (Exception e) {
e.printStackTrace();
} finally {
// 关闭资源
close(rs);
close(conn);
}
//
return result;
}
/**
* 根据IP,端口,以及数据库名字,拼接Oracle连接字符串
*
* @param ip
* @param port
* @param dbname
* @return
*/
public static String concatDBURL(DATABASETYPE dbtype, String ip, String port, String dbname) {
//
String url = "";
// Oracle数据库
if (DATABASETYPE.ORACLE.equals(dbtype)) {
//
url += "jdbc:oracle:thin:@";
url += ip.trim();
url += ":" + port.trim();
url += ":" + dbname;
// 如果需要采用 hotbackup
String url2 = "";
url2 = url2+"jdbc:oracle:thin:@(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = "
+ ip.trim() +")(PORT ="+ port.trim() +")))(CONNECT_DATA = (SERVICE_NAME ="+dbname+
")(FAILOVER_MODE = (TYPE = SELECT)(METHOD = BASIC)(RETRIES = 180)(DELAY = 5))))";
//
// url = url2;
} else if (DATABASETYPE.MYSQL.equals(dbtype)) {
//
url += "jdbc:mysql://";
url += ip.trim();
url += ":" + port.trim();
url += "/" + dbname;
} else if (DATABASETYPE.SQLSERVER.equals(dbtype)) {
//
url += "jdbc:jtds:sqlserver://";
url += ip.trim();
url += ":" + port.trim();
url += "/" + dbname;
url += ";tds=8.0;lastupdatecount=true";
} else if (DATABASETYPE.SQLSERVER2005.equals(dbtype)) {
//
url += "jdbc:sqlserver://";
url += ip.trim();
url += ":" + port.trim();
url += "; DatabaseName=" + dbname;
} else if (DATABASETYPE.DB2.equals(dbtype)) {
url += "jdbc:db2://";
url += ip.trim();
url += ":" + port.trim();
url += "/" + dbname;
} else if (DATABASETYPE.INFORMIX.equals(dbtype)) {
// Infox mix 可能有BUG
url += "jdbc:informix-sqli://";
url += ip.trim();
url += ":" + port.trim();
url += "/" + dbname;
// +":INFORMIXSERVER=myserver;user="+bean.getDatabaseuser()+";password="+bean.getDatabasepassword()
} else if (DATABASETYPE.SYBASE.equals(dbtype)) {
url += "jdbc:sybase:Tds:";
url += ip.trim();
url += ":" + port.trim();
url += "/" + dbname;
} else {
throw new RuntimeException("不认识的数据库类型!");
}
//
return url;
}
/**
* 获取JDBC连接
*
* @param url
* @param username
* @param password
* @return
*/
public static Connection getConnection(String url, String username, String password) {
Connection conn = null;
try {
// 不需要加载Driver. Servlet 2.4规范开始容器会自动载入
// conn = DriverManager.getConnection(url, username, password);
//
Properties info =new Properties();
//
info.put("user", username);
info.put("password", password);
// !!! Oracle 如果想要获取元数据 REMARKS 信息,需要加此参数
info.put("remarksReporting","true");
// !!! MySQL 标志位, 获取TABLE元数据 REMARKS 信息
info.put("useInformationSchema","true");
// 不知道SQLServer需不需要设置...
//
conn = DriverManager.getConnection(url, info);
} catch (SQLException e) {
e.printStackTrace();
}
return conn;
}
/**
* 将一个未处理的ResultSet解析为Map列表.
*
* @param rs
* @return
*/
public static List<Map<String, Object>> parseResultSetToMapList(ResultSet rs) {
//
List<Map<String, Object>> result = new ArrayList<Map<String, Object>>();
//
if (null == rs) {
return null;
}
//
try {
while (rs.next()) {
//
Map<String, Object> map = parseResultSetToMap(rs);
//
if (null != map) {
result.add(map);
}
}
} catch (SQLException e) {
e.printStackTrace();
}
//
return result;
}
/**
* 解析ResultSet的单条记录,不进行 ResultSet 的next移动处理
*
* @param rs
* @return
*/
private static Map<String, Object> parseResultSetToMap(ResultSet rs) {
//
if (null == rs) {
return null;
}
//
Map<String, Object> map = new HashMap<String, Object>();
//
try {
ResultSetMetaData meta = rs.getMetaData();
//
int colNum = meta.getColumnCount();
//
for (int i = 1; i <= colNum; i++) {
// 列名
String name = meta.getColumnLabel(i); // i+1
Object value = rs.getObject(i);
// 加入属性
map.put(name, value);
}
} catch (SQLException e) {
e.printStackTrace();
}
//
return map;
}
//
public static boolean TryLink(String databasetype, String ip, String port, String dbname, String username, String password) {
//
DATABASETYPE dbtype = parseDATABASETYPE(databasetype);
String url = concatDBURL(dbtype, ip, port, dbname);
Connection conn = null;
//
try {
conn = getConnection(url, username, password);
if(null == conn){
return false;
}
DatabaseMetaData meta = conn.getMetaData();
//
if(null == meta){
return false;
} else {
// 只有这里返回true
return true;
}
} catch (Exception e) {
e.printStackTrace();
} finally{
close(conn);
}
//
return false;
}
//
public static void close(Connection conn) {
if(conn!=null) {
try {
conn.close();
conn = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
}
//
public static void close(Statement stmt) {
if(stmt!=null) {
try {
stmt.close();
stmt = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
}
//
public static void close(ResultSet rs) {
if(rs!=null) {
try {
rs.close();
rs = null;
} catch (SQLException e) {
e.printStackTrace();
}
}
}
//
public static String trim(String str){
if(null != str){
str = str.trim();
}
return str;
}
public static void main(String[] args) {
//testLinkOracle();
//testLinkSQLServer();
testOracle();
//testMySQL();
}
//
public static void testLinkOracle() {
//
String ip= "192.168.0.100";
String port= "1521";
String dbname= "orcl";
String username= "username";
String password= "*****pwd";
String databasetype= "oracle";
//
String url = concatDBURL(parseDATABASETYPE(databasetype), ip, port, dbname);
System.out.println("url="+url);
//
boolean result = TryLink(databasetype, ip, port, dbname, username, password);
//
System.out.println("result="+result);
}
//
public static void testLinkSQLServer() {
//
String ip= "192.168.0.100";
String port= "1433";
String dbname= "sqlserverdb1";
String username= "sa";
String password= "186957";
String databasetype= "SQL Server";
//
String url = concatDBURL(parseDATABASETYPE(databasetype), ip, port, dbname);
System.out.println("url="+url);
//
boolean result = TryLink(databasetype, ip, port, dbname, username, password);
//
System.out.println("result="+result);
}
public static void testOracle() {
//
String ip = "192.168.0.100";
String port = "1521";
String dbname = "orcl";
String username = "unixsys";
String password = "orpass";
//
String databasetype = "Oracle";
// DATABASETYPE dbtype = parseDATABASETYPE(databasetype);
// System.out.println(DATABASETYPE.ORACLE.equals(dbtype));
//
String tableName = "DBMS_CODE_CHEME_NEW";
List<Map<String, Object>> tables = listTables(databasetype, ip, port, dbname, username, password);
List<Map<String, Object>> columns = listColumns(databasetype, ip, port, dbname, username, password, tableName);
//
tables = MapUtil.convertKeyList2LowerCase(tables);
columns = MapUtil.convertKeyList2LowerCase(columns);
//
String jsonT = JSONArray.toJSONString(tables, true);
System.out.println(jsonT);
System.out.println("tables.size()=" + tables.size());
//
System.out.println("-----------------------------------------" + "-----------------------------------------");
System.out.println("-----------------------------------------" + "-----------------------------------------");
//
String jsonC = JSONArray.toJSONString(columns, true);
System.out.println(jsonC);
System.out.println("columns.size()=" + columns.size());
}
public static void testMySQL() {
//
String ip = "127.0.0.1";
String port = "4050";
String
dbname = "cncounter";
dbname = "eReqDlG";
String
username = "root";
username = "6EhSiGpsmSMRr";
String
password = "eoNRNBgRk397mVy";
//
String databasetype = "mysql";
// DATABASETYPE dbtype = parseDATABASETYPE(databasetype);
// System.out.println(DATABASETYPE.ORACLE.equals(dbtype));
//
String tableName = "vote";
List<Map<String, Object>> tables = listTables(databasetype, ip, port, dbname, username, password);
List<Map<String, Object>> columns = listColumns(databasetype, ip, port, dbname, username, password, tableName);
//
tables = MapUtil.convertKeyList2LowerCase(tables);
columns = MapUtil.convertKeyList2LowerCase(columns);
//
String jsonT = JSONArray.toJSONString(tables, true);
System.out.println(jsonT);
System.out.println("tables.size()=" + tables.size());
//
System.out.println("-----------------------------------------" + "-----------------------------------------");
System.out.println("-----------------------------------------" + "-----------------------------------------");
//
String jsonC = JSONArray.toJSONString(columns, true);
System.out.println(jsonC);
System.out.println("columns.size()=" + columns.size());
}
// 演示 DatabaseMetaData
public static void demoDatabaseMetaData() {
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/dbtest", "root", "root");
//
DatabaseMetaData dmd = con.getMetaData();
System.out.println("当前数据库是：" + dmd.getDatabaseProductName());
System.out.println("当前数据库版本：" + dmd.getDatabaseProductVersion());
System.out.println("当前数据库驱动：" + dmd.getDriverVersion());
System.out.println("当前数据库URL：" + dmd.getURL());
System.out.println("当前数据库是否是只读模式？：" + dmd.isReadOnly());
System.out.println("当前数据库是否支持批量更新？：" + dmd.supportsBatchUpdates());
System.out.println("当前数据库是否支持结果集的双向移动（数据库数据变动不在ResultSet体现）？："
+ dmd.supportsResultSetType(ResultSet.TYPE_SCROLL_INSENSITIVE));
System.out.println("当前数据库是否支持结果集的双向移动（数据库数据变动会影响到ResultSet的内容）？："
+ dmd.supportsResultSetType(ResultSet.TYPE_SCROLL_SENSITIVE));
System.out.println("========================================");
ResultSet rs = dmd.getTables(null, null, "%", null);
System.out.println("表名" + "," + "表类型");
while (rs.next()) {
System.out.println(rs.getString("TABLE_NAME") + "," + rs.getString("TABLE_TYPE"));
}
System.out.println("========================================");
rs = dmd.getPrimaryKeys(null, null, "t_student");
while (rs.next()) {
System.out.println(rs.getString(3) + "表的主键是：" + rs.getString(4));
}
System.out.println("========================================");
rs = dmd.getColumns(null, null, "t_student", "%");
System.out.println("t_student表包含的字段:");
while (rs.next()) {
System.out.println(rs.getString(4) + " " + rs.getString(6) + "(" + rs.getString(7) + ");");
}
System.out.println("========================================");
} catch (Exception e) {
System.out.println("数据库操作出现异常");
}
}
// ResultSetMetaData 使用示例
// 此方法参考 http://blog.csdn.net/yirentianran/article/details/2950321
public static void demoResultSetMetaData(ResultSetMetaData data) throws SQLException {
for (int i = 1; i <= data.getColumnCount(); i++) {
// 获得所有列的数目及实际列数
int columnCount = data.getColumnCount();
// 获得指定列的列名
String columnName = data.getColumnName(i);
// 获得指定列的列值
// String columnValue = rs.getString(i);
// 获得指定列的数据类型
int columnType = data.getColumnType(i);
// 获得指定列的数据类型名
String columnTypeName = data.getColumnTypeName(i);
// 所在的Catalog名字
String catalogName = data.getCatalogName(i);
// 对应数据类型的类
String columnClassName = data.getColumnClassName(i);
// 在数据库中类型的最大字符个数
int columnDisplaySize = data.getColumnDisplaySize(i);
// 默认的列的标题
String columnLabel = data.getColumnLabel(i);
// 获得列的模式
String schemaName = data.getSchemaName(i);
// 某列类型的精确度(类型的长度)
int precision = data.getPrecision(i);
// 小数点后的位数
int scale = data.getScale(i);
// 获取某列对应的表名
String tableName = data.getTableName(i);
// 是否自动递增
boolean isAutoInctement = data.isAutoIncrement(i);
// 在数据库中是否为货币型
boolean isCurrency = data.isCurrency(i);
// 是否为空
int isNullable = data.isNullable(i);
// 是否为只读
boolean isReadOnly = data.isReadOnly(i);
// 能否出现在where中
boolean isSearchable = data.isSearchable(i);
System.out.println(columnCount);
System.out.println("获得列" + i + "的字段名称:" + columnName);
// System.out.println("获得列" + i + "的字段值:" + columnValue);
System.out.println("获得列" + i + "的类型,返回SqlType中的编号:" + columnType);
System.out.println("获得列" + i + "的数据类型名:" + columnTypeName);
System.out.println("获得列" + i + "所在的Catalog名字:" + catalogName);
System.out.println("获得列" + i + "对应数据类型的类:" + columnClassName);
System.out.println("获得列" + i + "在数据库中类型的最大字符个数:" + columnDisplaySize);
System.out.println("获得列" + i + "的默认的列的标题:" + columnLabel);
System.out.println("获得列" + i + "的模式:" + schemaName);
System.out.println("获得列" + i + "类型的精确度(类型的长度):" + precision);
System.out.println("获得列" + i + "小数点后的位数:" + scale);
System.out.println("获得列" + i + "对应的表名:" + tableName);
System.out.println("获得列" + i + "是否自动递增:" + isAutoInctement);
System.out.println("获得列" + i + "在数据库中是否为货币型:" + isCurrency);
System.out.println("获得列" + i + "是否为空:" + isNullable);
System.out.println("获得列" + i + "是否为只读:" + isReadOnly);
System.out.println("获得列" + i + "能否出现在where中:" + isSearchable);
}
}
}

转自 http://blog.csdn.net/renfufei/article/details/39316751/

需要整理后才能发布若转载请注明出处！若有疑问，请回复交流！

使用JDBC获取各数据库的Meta信息——表以及对应的列

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