java获取mysql表结构

获取表结构与字段信息：


package com.mysql;


import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import java.sql.Types;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.AbstractMap.SimpleEntry;
import java.util.Map.Entry;
public class TestDbMetaData {
@SuppressWarnings("unchecked")
public static void main(String[] args) throws Exception {
String dburl = "jdbc:mysql://127.0.0.1:3306/fhadmin";
String dbuser = "root";
String dbpwd = "root";
Class.forName("com.mysql.jdbc.Driver");
List<String> tableName = new ArrayList<String>();
Map<String, List<Entry<String, String>>> tables = new HashMap<String, List<Entry<String, String>>>();
Connection con = DriverManager.getConnection(dburl, dbuser, dbpwd);
DatabaseMetaData metaDb = con.getMetaData();
ResultSet rsTableName = metaDb.getTables(null, null, null, new String[] { "table" });
while (rsTableName.next()) {
String tmpTableName = rsTableName.getString("table_name");
tableName.add(tmpTableName);
String sql = "select * from " + tmpTableName;
Statement st = con.createStatement();
ResultSet rsColumName = st.executeQuery(sql);
ResultSetMetaData metaRs = rsColumName.getMetaData();
List<Entry<String, String>> colums = new ArrayList<Entry<String, String>>();
for (int i = 1; i <= metaRs.getColumnCount(); i++) {
System.out.print( metaRs.getColumnName(i)+","+metaRs.getColumnClassName(i).substring(metaRs.getColumnClassName(i).lastIndexOf(".") + 1));
System.out.println(",是否为空："+metaRs.isNullable(i));//0 不能为空   1可以为空
    //System.out.println(metaRs.getColumnLabel(i));
    //System.out.println(metaRs.getColumnDisplaySize(i));
String columName = metaRs.getColumnName(i);
// 某列类型的精确度(类型的长度)
                int precision = metaRs.getPrecision(i);
                // 小数点后的位数 
                int scale = metaRs.getScale(i);
                // 是否自动递增 
                boolean isAutoInctement = metaRs.isAutoIncrement(i);
String aa= metaRs.getColumnTypeName(i);
String columType = "";
switch (metaRs.getColumnType(i )) {
case Types.CHAR:
columType = "String";
break;
case Types.BIGINT:
columType = "int";
break;
case Types.DATE:
columType = "Date";
break;
case Types.DECIMAL:
columType = "int";
break;
case Types.INTEGER:
columType = "int";
break;
case Types.NCHAR:
columType = "String";
break;
case Types.NUMERIC:
columType = "int";
break;
case Types.NVARCHAR:
columType = "String";
break;
case Types.SMALLINT:
columType = "int";
break;
case Types.TIME:
columType = "Date";
break;
case Types.TINYINT:
columType = "int";
break;
case Types.TIMESTAMP:
columType = "Date";
break;
case Types.VARCHAR:
columType = "String";
break;
default:
throw new Exception("数据类型不支持，orm映射异常");
}
Entry<String, String> entry = new SimpleEntry(columName, columType);
colums.add(entry);
}
tables.put(tmpTableName, colums);
}


Iterator<Entry<String, List<Entry<String, String>>>> iter = tables.entrySet().iterator();
while (iter.hasNext()) {
Entry<String, List<Entry<String, String>>> entry = iter.next();
System.out.println("表名：" + entry.getKey());
for (int i = 0; i < entry.getValue().size(); i++) {
System.out.print(entry.getValue().get(i).getKey() + " " + entry.getValue().get(i).getValue());
}
System.out.println();
}
System.out.println("complete...");
}
}