📄 java研究组织 - 精品文章 - 使用jboss和postgresql-----快速开发ejb和j2ee web application.htm
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class=classLink><U>SQLException</U></FONT></A></B>;
<LI><B><FONT
color=#0000ff>import</FONT></B> java.sql.<B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/Statement.java.html"
target=_blank><FONT
class=classLink><U>Statement</U></FONT></A></B>;
<LI><B><FONT
color=#0000ff>import</FONT></B> java.sql.<B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/ResultSet.java.html"
target=_blank><FONT
class=classLink><U>ResultSet</U></FONT></A></B>;
<LI>
<LI><B><FONT
color=#0000ff>import</FONT></B> javax.naming.<B><A
href="http://www.javaresearch.org/source/jdk142/javax/naming/InitialContext.java.html"
target=_blank><FONT
class=classLink><U>InitialContext</U></FONT></A></B>;
<LI><B><FONT
color=#0000ff>import</FONT></B> javax.sql.<B><A
href="http://www.javaresearch.org/source/jdk142/javax/sql/DataSource.java.html"
target=_blank><FONT
class=classLink><U>DataSource</U></FONT></A></B>;
<LI>
<LI>
<LI><B><FONT
color=#0000ff>public</FONT></B> <B><FONT
color=#0000ff>class</FONT></B> MysqlDao {
<LI>
<LI> <B><FONT
color=#0000ff>public</FONT></B> <B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/Connection.java.html"
target=_blank><FONT
class=classLink><U>Connection</U></FONT></A></B> getConnection() <B><FONT
color=#0000ff>throws</FONT></B> <B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/Exception.java.html"
target=_blank><FONT
class=classLink><U>Exception</U></FONT></A></B> {
<LI>
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/javax/naming/InitialContext.java.html"
target=_blank><FONT
class=classLink><U>InitialContext</U></FONT></A></B> ctx = <B><FONT
color=#0000ff>new</FONT></B> <B><A
href="http://www.javaresearch.org/source/jdk142/javax/naming/InitialContext.java.html"
target=_blank><FONT
class=classLink><U>InitialContext</U></FONT></A></B>();
<LI>
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/javax/sql/DataSource.java.html"
target=_blank><FONT
class=classLink><U>DataSource</U></FONT></A></B> ds = (<B><A
href="http://www.javaresearch.org/source/jdk142/javax/sql/DataSource.java.html"
target=_blank><FONT
class=classLink><U>DataSource</U></FONT></A></B>) ctx.lookup(<FONT
color=#ff33ff>"java:/PostgresDS"</FONT>);
<LI>
<LI>
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/Connection.java.html"
target=_blank><FONT
class=classLink><U>Connection</U></FONT></A></B> conn = <B><FONT
color=#0000ff>null</FONT></B>;
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/Statement.java.html"
target=_blank><FONT
class=classLink><U>Statement</U></FONT></A></B> stmt = <B><FONT
color=#0000ff>null</FONT></B>;
<LI>
<LI> <B><FONT
color=#0000ff>try</FONT></B> {
<LI> conn = ds.getConnection();
<LI>
<LI> } <B><FONT
color=#0000ff>catch</FONT></B> (<B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/SQLException.java.html"
target=_blank><FONT
class=classLink><U>SQLException</U></FONT></A></B> sqlEx) {
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/System.java.html"
target=_blank><FONT
class=classLink><U>System</U></FONT></A></B>.out.println(<FONT
color=#ff33ff>"Error connect to pool."</FONT>);
<LI> }
<LI>
<LI> <B><FONT
color=#0000ff>return</FONT></B> conn;
<LI> }
<LI>
<LI> <B><FONT
color=#0000ff>public</FONT></B> <B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/String.java.html"
target=_blank><FONT
class=classLink><U>String</U></FONT></A></B> getName(<B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/String.java.html"
target=_blank><FONT
class=classLink><U>String</U></FONT></A></B> id) <B><FONT
color=#0000ff>throws</FONT></B> <B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/Exception.java.html"
target=_blank><FONT
class=classLink><U>Exception</U></FONT></A></B> {
<LI>
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/Connection.java.html"
target=_blank><FONT
class=classLink><U>Connection</U></FONT></A></B> conn = <B><FONT
color=#0000ff>null</FONT></B>;
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/Statement.java.html"
target=_blank><FONT
class=classLink><U>Statement</U></FONT></A></B> stmt = <B><FONT
color=#0000ff>null</FONT></B>;
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/sql/ResultSet.java.html"
target=_blank><FONT
class=classLink><U>ResultSet</U></FONT></A></B> rs = <B><FONT
color=#0000ff>null</FONT></B>;
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/String.java.html"
target=_blank><FONT
class=classLink><U>String</U></FONT></A></B> name = <FONT
color=#ff33ff>""</FONT>;
<LI>
<LI> <B><FONT
color=#0000ff>try</FONT></B> {
<LI> conn = getConnection();
<LI> <B><FONT
color=#0000ff>if</FONT></B> ( conn !=<B><FONT
color=#0000ff>null</FONT></B> )<B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/System.java.html"
target=_blank><FONT
class=classLink><U>System</U></FONT></A></B>.out.println(<FONT
color=#ff33ff>"Get conecttion. "</FONT>+ conn.toString());
<LI> stmt = conn.createStatement();
<LI> <B><FONT
color=#0000ff>if</FONT></B> ( stmt !=<B><FONT
color=#0000ff>null</FONT></B> )<B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/System.java.html"
target=_blank><FONT
class=classLink><U>System</U></FONT></A></B>.out.println(<FONT
color=#ff33ff>"Get Statement. "</FONT>+ stmt.toString());
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/String.java.html"
target=_blank><FONT
class=classLink><U>String</U></FONT></A></B> sql = <FONT
color=#ff33ff>"SELECT * from users where id = '"</FONT>+id+<FONT
color=#ff33ff>"'"</FONT>;
<LI> <B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/System.java.html"
target=_blank><FONT
class=classLink><U>System</U></FONT></A></B>.out.println(<FONT
color=#ff33ff>"Sql from getId(): "</FONT>+sql);
<LI> rs = stmt.executeQuery(sql);
<LI> <B><FONT
color=#0000ff>if</FONT></B> ( rs !=<B><FONT
color=#0000ff>null</FONT></B> )<B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/System.java.html"
target=_blank><FONT
class=classLink><U>System</U></FONT></A></B>.out.println(<FONT
color=#ff33ff>"Get result. "</FONT>);
<LI> <B><FONT
color=#0000ff>if</FONT></B> (rs.next()){
<LI> name = rs.getString(<FONT
color=#ff33ff>"name"</FONT>);
<LI> }
<LI>
<LI> } <B><FONT
color=#0000ff>catch</FONT></B> (<B><A
href="http://www.javaresearch.org/source/jdk142/java/lang/Exception.java.html"
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