public class ReportView extends JFrame {
Connection con=null;
void showReport() throws SQLException, ClassNotFoundException, JRException {
con=DriverManager.getConnection("jdbc:postgresql://localhost:5432/Test");
JasperReport report=JasperCompileManager.compileReport("Testing.jrxml");
JasperPrint print=JasperFillManager.fillReport(report,null,con);
JRViewer viewer=new JRViewer(print);
viewer.setOpaque(true);
viewer.setVisible(true);
this.add(viewer);
this.setSize(300, 200);
this.setVisible(true);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
这是错误：
Exception in thread "main" java.sql.SQLException: No suitable driver found for jdbc:postgresql://localhost:5432/Test
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
有什么不对？
答案 0 :(得分：26)
Class.forName("org.postgresql.Driver"); 答案 1 :(得分：6)
您需要将postgreSQL JDBC驱动程序放在类路径上。
有关说明，请参阅official documentation。
答案 2 :(得分：2)
您是否将Postgresql驱动程序添加到类路径中？
答案 3 :(得分：0)
我不知道，但这对我来说非常合适。我在Sun和PostgreSQL 8.1本地运行JDK 1.6.0_21：
package persistence;
import java.sql.*;
import java.util.*;
/**
* util.DatabaseUtils
* User: Michael
* Date: Aug 17, 2010
* Time: 7:58:02 PM
*/
public class DatabaseUtils
{
private static final String DEFAULT_DRIVER = "org.postgresql.Driver";
private static final String DEFAULT_URL = "jdbc:postgresql://localhost:5432/party";
private static final String DEFAULT_USERNAME = "pgsuper";
private static final String DEFAULT_PASSWORD = "pgsuper";
/*
private static final String DEFAULT_DRIVER = "com.mysql.jdbc.Driver";
private static final String DEFAULT_URL = "jdbc:mysql://localhost:3306/party";
private static final String DEFAULT_USERNAME = "party";
private static final String DEFAULT_PASSWORD = "party";
*/
public static void main(String[] args)
{
long begTime = System.currentTimeMillis();
String driver = ((args.length > 0) ? args[0] : DEFAULT_DRIVER);
String url = ((args.length > 1) ? args[1] : DEFAULT_URL);
String username = ((args.length > 2) ? args[2] : DEFAULT_USERNAME);
String password = ((args.length > 3) ? args[3] : DEFAULT_PASSWORD);
Connection connection = null;
try
{
connection = createConnection(driver, url, username, password);
DatabaseMetaData meta = connection.getMetaData();
System.out.println(meta.getDatabaseProductName());
System.out.println(meta.getDatabaseProductVersion());
String sqlQuery = "SELECT PERSON_ID, FIRST_NAME, LAST_NAME FROM PERSON ORDER BY LAST_NAME";
System.out.println("before insert: " + query(connection, sqlQuery, Collections.EMPTY_LIST));
connection.setAutoCommit(false);
String sqlUpdate = "INSERT INTO PERSON(FIRST_NAME, LAST_NAME) VALUES(?,?)";
List parameters = Arrays.asList( "Foo", "Bar" );
int numRowsUpdated = update(connection, sqlUpdate, parameters);
connection.commit();
System.out.println("# rows inserted: " + numRowsUpdated);
System.out.println("after insert: " + query(connection, sqlQuery, Collections.EMPTY_LIST));
}
catch (Exception e)
{
rollback(connection);
e.printStackTrace();
}
finally
{
close(connection);
long endTime = System.currentTimeMillis();
System.out.println("wall time: " + (endTime - begTime) + " ms");
}
}
public static Connection createConnection(String driver, String url, String username, String password) throws ClassNotFoundException, SQLException
{
Class.forName(driver);
if ((username == null) || (password == null) || (username.trim().length() == 0) || (password.trim().length() == 0))
{
return DriverManager.getConnection(url);
}
else
{
return DriverManager.getConnection(url, username, password);
}
}
public static void close(Connection connection)
{
try
{
if (connection != null)
{
connection.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void close(Statement st)
{
try
{
if (st != null)
{
st.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void close(ResultSet rs)
{
try
{
if (rs != null)
{
rs.close();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static void rollback(Connection connection)
{
try
{
if (connection != null)
{
connection.rollback();
}
}
catch (SQLException e)
{
e.printStackTrace();
}
}
public static List<Map<String, Object>> map(ResultSet rs) throws SQLException
{
List<Map<String, Object>> results = new ArrayList<Map<String, Object>>();
try
{
if (rs != null)
{
ResultSetMetaData meta = rs.getMetaData();
int numColumns = meta.getColumnCount();
while (rs.next())
{
Map<String, Object> row = new HashMap<String, Object>();
for (int i = 1; i <= numColumns; ++i)
{
String name = meta.getColumnName(i);
Object value = rs.getObject(i);
row.put(name, value);
}
results.add(row);
}
}
}
finally
{
close(rs);
}
return results;
}
public static List<Map<String, Object>> query(Connection connection, String sql, List<Object> parameters) throws SQLException
{
List<Map<String, Object>> results = null;
PreparedStatement ps = null;
ResultSet rs = null;
try
{
ps = connection.prepareStatement(sql);
int i = 0;
for (Object parameter : parameters)
{
ps.setObject(++i, parameter);
}
rs = ps.executeQuery();
results = map(rs);
}
finally
{
close(rs);
close(ps);
}
return results;
}
public static int update(Connection connection, String sql, List<Object> parameters) throws SQLException
{
int numRowsUpdated = 0;
PreparedStatement ps = null;
try
{
ps = connection.prepareStatement(sql);
int i = 0;
for (Object parameter : parameters)
{
ps.setObject(++i, parameter);
}
numRowsUpdated = ps.executeUpdate();
}
finally
{
close(ps);
}
return numRowsUpdated;
}
}
这是结果：
PostgreSQL
8.1.3
before insert: [{first_name=Foo, person_id=55, last_name=Bar}, {first_name=Foo, person_id=52, last_name=Bar}, {first_name=Foo, person_id=53, last_name=Bar}, {first_name=Foo, person_id=54, last_name=Bar}, {first_name=Foo, person_id=56, last_name=Bar}, {first_name=SEAMUS, person_id=2, last_name=DUFFY}, {first_name=MICHAEL, person_id=1, last_name=DUFFY}]
# rows inserted: 1
after insert: [{first_name=Foo, person_id=56, last_name=Bar}, {first_name=Foo, person_id=52, last_name=Bar}, {first_name=Foo, person_id=53, last_name=Bar}, {first_name=Foo, person_id=54, last_name=Bar}, {first_name=Foo, person_id=55, last_name=Bar}, {first_name=Foo, person_id=57, last_name=Bar}, {first_name=SEAMUS, person_id=2, last_name=DUFFY}, {first_name=MICHAEL, person_id=1, last_name=DUFFY}]
wall time: 344 ms