MySQL操作blob的经验研讨
以下的文章主要讲述的是MySQL操作blob的经验研讨,如果你在MySQL操作blob的实际操作中有不解之处时,你可以通过以下的文章对其的实际应用与功能有所了解,下面是文章的具体介绍,望你浏览完以下的内容会有所收获。 jsp(SUN企业级应用的首选)+MySQL(和PHP搭配
以下的文章主要讲述的是MySQL操作blob的经验研讨,如果你在MySQL操作blob的实际操作中有不解之处时,你可以通过以下的文章对其的实际应用与功能有所了解,下面是文章的具体介绍,望你浏览完以下的内容会有所收获。
jsp(SUN企业级应用的首选)+MySQL(和PHP搭配之最佳组合) 记住 要用MySQL(和PHP搭配之最佳组合)的longblob类型来存默认的MySQL操作blob大小不够
数据库字段:id (char) pic (longblob)
转载请注明出处,这时我与我的知己的合作的结过
原来操作blob字段时都要先差个空值,在查blob,好麻烦,用prepareStatment就不用那么麻烦了,哈哈
postblob.heml页面
<ol class="dp-xml"> <li class="alt"><span><span>nbsp;html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">html</span><span> xml(标准化越来越近了)</span><span class="attribute">ns</span><span>=</span><span class="attribute-value">"http://www.w3.org/1999/xhtml"</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">meta</span><span> </span><span class="attribute">http-equiv</span><span>=</span><span class="attribute-value">"Content-Type"</span><span> </span><span class="attribute">content</span><span>=</span><span class="attribute-value">"text/html; charset=gb2312"</span><span> </span><span class="tag">/></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">title</span><span class="tag">></span><span>无标题文档</span><span class="tag"></span><span class="tag-name">title</span><span class="tag">></span><span> </span></span></li> <li> <span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span> </span> </li> <li class="alt"><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">form</span><span> </span><span class="attribute">action</span><span>=</span><span class="attribute-value">"testblob.jsp(SUN企业级应用的首选)"</span><span> </span><span class="attribute">method</span><span>=</span><span class="attribute-value">"post"</span><span> </span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">table</span><span> </span><span class="attribute">width</span><span>=</span><span class="attribute-value">"291"</span><span> </span><span class="attribute">border</span><span>=</span><span class="attribute-value">"1"</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">tr</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">td</span><span> </span><span class="attribute">width</span><span>=</span><span class="attribute-value">"107"</span><span class="tag">></span><span>id </span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">td</span><span> </span><span class="attribute">width</span><span>=</span><span class="attribute-value">"168"</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">name</span><span>=</span><span class="attribute-value">"id"</span><span> </span><span class="attribute">type</span><span>=</span><span class="attribute-value">"text"</span><span> </span><span class="tag">/></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span> </span></span></span></li> <li class="alt"> <span class="tag"></span><span class="tag-name">tr</span><span class="tag">></span><span> </span> </li> <li><span class="tag"><span class="tag-name">tr</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span>file</span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">name</span><span>=</span><span class="attribute-value">"file"</span><span> </span><span class="attribute">type</span><span>=</span><span class="attribute-value">"file"</span><span> </span><span class="tag">/></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span> </span></span></span></li> <li class="alt"> <span class="tag"></span><span class="tag-name">tr</span><span class="tag">></span><span> </span> </li> <li><span class="tag"><span class="tag-name">tr</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">type</span><span>=</span><span class="attribute-value">"submit"</span><span> </span><span class="attribute">value</span><span>=</span><span class="attribute-value">"提交"</span><span class="tag">/></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span> </span></span></span></li> <li> <span class="tag"></span><span class="tag-name">tr</span><span class="tag">></span><span> </span> </li> <li class="alt"> <span class="tag"></span><span class="tag-name">table</span><span class="tag">></span><span> </span> </li> <li> <span class="tag"></span><span class="tag-name">form</span><span class="tag">></span><span> </span> </li> <li class="alt"> <span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span> </span> </li> <li> <span class="tag"></span><span class="tag-name">html</span><span class="tag">></span><span> </span> </li> <li class="alt"><span>testblob.jsp(SUN企业级应用的首选) </span></li> <li><span class="tag"><span>%@ page </span><span class="attribute">contentType</span><span>=</span><span class="attribute-value">"text/html;charset=gb2312"</span><span>%</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span>%@ page </span><span class="attribute">import</span><span>=</span><span class="attribute-value">"java.sql.*"</span><span> %</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span>%@ page </span><span class="attribute">import</span><span>=</span><span class="attribute-value">"java.util.*"</span><span>%</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span>%@ page </span><span class="attribute">import</span><span>=</span><span class="attribute-value">"java.text.*"</span><span>%</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span>%@ page </span><span class="attribute">import</span><span>=</span><span class="attribute-value">"java.io.*"</span><span>%</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">html</span><span> xml(标准化越来越近了)</span><span class="attribute">ns</span><span>=</span><span class="attribute-value">"http://www.w3.org/1999/xhtml"</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">meta</span><span> </span><span class="attribute">http-equiv</span><span>=</span><span class="attribute-value">"Content-Type"</span><span> </span><span class="attribute">content</span><span>=</span><span class="attribute-value">"text/html; charset=gb2312"</span><span> </span><span class="tag">/></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">title</span><span class="tag">></span><span>无标题文档</span><span class="tag"></span><span class="tag-name">title</span><span class="tag">></span><span> </span></span></li> <li class="alt"> <span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span> </span> </li> <li><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span>% </span></span></li> <li> <span>String </span><span class="attribute">id</span><span>=</span><span class="attribute-value">request</span><span>.getParameter("id"); </span> </li> <li class="alt"> <span>String </span><span class="attribute">file</span><span>=</span><span class="attribute-value">request</span><span>.getParameter("file"); </span> </li> <li><span>out.print(id); </span></li> <li class="alt"><span>out.print(file); </span></li> <li> <span>FileInputStream </span><span class="attribute">str</span><span>=</span><span class="attribute-value">new</span><span> FileInputStream(file); </span> </li> <li class="alt"><span>out.print(str.available()); </span></li> <li><span>java.sql.Connection conn; </span></li> <li class="alt"><span>java.lang.String strConn; </span></li> <li> <span>Class.forName("org.gjt.mm.</span>MySQL<span>(和PHP搭配之最佳组合).Driver").newInstance(); </span> </li> <li class="alt"> <span class="attribute">conn</span><span>= </span><span class="attribute-value">java</span><span>.sql.DriverManager.getConnection("jdbc:</span>MySQL<span>(和PHP搭配之最佳组合)://localhost/test","root",""); </span> </li> <li> <span>String </span><span class="attribute">sql</span><span>=</span><span class="attribute-value">"insert into test(id,pic) values(?,?)"</span><span>; </span> </li> <li class="alt"> <span>PreparedStatement </span><span class="attribute">pstmt</span><span>=</span><span class="attribute-value">conn</span><span>.prepareStatement(sql); </span> </li> <li><span>pstmt.setString(1,id); </span></li> <li class="alt"><span>pstmt.setBinaryStream(2,str,str.available()); </span></li> <li><span>pstmt.execute(); </span></li> <li class="alt"><span>out.println("Success,You Have Insert an Image Successfully"); </span></li> <li><span>pstmt.close(); </span></li> <li class="alt"> <span>%</span><span class="tag">></span><span> </span> </li> <li><span class="tag"><span class="tag-name">a</span><span> </span><span class="attribute">href</span><span>=</span><span class="attribute-value">"readblob.jsp(SUN企业级应用的首选)"</span><span class="tag">></span><span>查看图片</span><span class="tag"></span><span class="tag-name">a</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">a</span><span> </span><span class="attribute">href</span><span>=</span><span class="attribute-value">"postblob.html"</span><span class="tag">></span><span>返回</span><span class="tag"></span><span class="tag-name">a</span><span class="tag">></span><span> </span></span></li> <li> <span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span> </span> </li> <li class="alt"> <span class="tag"></span><span class="tag-name">html</span><span class="tag">></span><span> </span> </li> <li><span>readblob.jsp(SUN企业级应用的首选) </span></li> <li class="alt"><span class="tag"><span>%@ page </span><span class="attribute">contentType</span><span>=</span><span class="attribute-value">"text/html;charset=gb2312"</span><span>%</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span>%@ page </span><span class="attribute">import</span><span>=</span><span class="attribute-value">"java.sql.*, javax.sql.*"</span><span> %</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span>%@ page </span><span class="attribute">import</span><span>=</span><span class="attribute-value">"java.util.*"</span><span>%</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span>%@ page </span><span class="attribute">import</span><span>=</span><span class="attribute-value">"java.text.*"</span><span>%</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span>%@ page </span><span class="attribute">import</span><span>=</span><span class="attribute-value">"java.io.*"</span><span>%</span><span class="tag">></span><span> </span></span></li> <li> <span>nbsp;html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"</span><span class="tag">></span><span> </span> </li> <li class="alt"><span class="tag"><span class="tag-name">html</span><span> xml(标准化越来越近了)</span><span class="attribute">ns</span><span>=</span><span class="attribute-value">"http://www.w3.org/1999/xhtml"</span><span class="tag">></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span class="tag-name">meta</span><span> </span><span class="attribute">http-equiv</span><span>=</span><span class="attribute-value">"Content-Type"</span><span> </span><span class="attribute">content</span><span>=</span><span class="attribute-value">"text/html; charset=gb2312"</span><span> </span><span class="tag">/></span><span> </span></span></li> <li><span class="tag"><span class="tag-name">title</span><span class="tag">></span><span>无标题文档</span><span class="tag"></span><span class="tag-name">title</span><span class="tag">></span><span> </span></span></li> <li class="alt"> <span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span> </span> </li> <li><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span> </span></span></li> <li class="alt"><span class="tag"><span>% </span></span></li> <li><span>java.sql.Connection conn; </span></li> <li class="alt"> <span>ResultSet </span><span class="attribute">rs</span><span>=</span><span class="attribute-value">null</span><span>; </span> </li> <li> <span>Class.forName("org.gjt.mm.</span>MySQL<span>(和PHP搭配之最佳组合).Driver").newInstance(); </span> </li> <li class="alt"> <span class="attribute">conn</span><span>= </span><span class="attribute-value">java</span><span>.sql.DriverManager.getConnection("jdbc:</span>MySQL<span>(和PHP搭配之最佳组合)://localhost/test","root",""); </span> </li> <li> <span>Statement </span><span class="attribute">stmt</span><span>=</span><span class="attribute-value">conn</span><span>.createStatement(); </span> </li> <li class="alt"> <span class="attribute">rs</span><span>=</span><span class="attribute-value">stmt</span><span>.executeQuery("select * from test where </span><span class="attribute">id</span><span>=</span><span class="attribute-value">'1'</span><span>"); </span> </li> <li><span>if(rs.next()) </span></li> <li class="alt"><span>{ </span></li> <li> <span>Blob </span><span class="attribute">b</span><span> = </span><span class="attribute-value">rs</span><span>.getBlob("pic"); </span> </li> <li class="alt"> <span>int </span><span class="attribute">size</span><span> =(int)b.length(); </span> </li> <li><span>out.print(size); </span></li> <li class="alt"> <span>InputStream </span><span class="attribute">in</span><span>=</span><span class="attribute-value">b</span><span>.getBinaryStream(); </span> </li> <li> <span>byte[] </span><span class="attribute">by</span><span>= </span><span class="attribute-value">new</span><span> byte[size]; </span> </li> <li class="alt"><span>response.setContentType("image/jpeg"); </span></li> <li> <span>ServletOutputStream </span><span class="attribute">sos</span><span> = </span><span class="attribute-value">response</span><span>.getOutputStream(); </span> </li> <li class="alt"> <span>int </span><span class="attribute">bytesRead</span><span> = </span><span class="attribute-value">0</span><span>; </span> </li> <li> <span>while ((</span><span class="attribute">bytesRead</span><span> = </span><span class="attribute-value">in</span><span>.read(by)) != -1) { </span> </li> <li class="alt"><span>sos.write(by, 0, bytesRead); </span></li> <li><span>} </span></li> <li class="alt"><span>in.close(); </span></li> <li><span>sos.flush(); </span></li> <li class="alt"><span>} </span></li> <li> <span>%</span><span class="tag">></span><span> </span> </li> <li class="alt"> <span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span> </span> </li> <li> <span class="tag"></span><span class="tag-name">html</span><span class="tag">></span><span> </span> </li> </ol>
注意:在用sos.write(by, 0, bytesRead);时,该方法把inputstream中的内容在一个新的页面中输出,
如果本页中还有别的内容要输出的话,只有把上述方法改为,bytesRead = in.read(by)) ;
再用out.print(new String(by));方法输出结果,注意在这里不能用by.toString()方法,该方法返回的是要输出内容的内存地址。MySQL(和PHP搭配之最佳组合)中有MySQL操作blob textarea类型大小了66536基本上放点小的东东就足够了,哈哈,但是现在的数码pic越来越大就只能用longblob了。

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