commons fileupload（Apache）
[英]commons fileupload(Apache)
問題描述
我在這里得到空指針異常：
List fileItems = upload.parseRequest(req);
如果文件中的行數大於2000，則會發生這種情況，因為我可以上傳1000行以上的行。有人請幫幫我。 表格如下。
<form name="fos_picks" id="fos_picks" action="<%=path%>/fos_upld" method="post" enctype="multipart/form-data" >
<br/><br/><br/><br/>
<p align="center">
<input type="file" name="file" size="50" /><br/>
<br/>
<input type="submit" class="buttons" value="Upload File" />
</p>
</form>
上傳控制器代碼......
package file_proc;
import DBConn.DBConn;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.sql.PreparedStatement;
import java.util.Iterator;
import java.util.List;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
@WebServlet(name="file_upld", urlPatterns = {"/file_upld"})
public class file_upld extends HttpServlet {
private boolean isMultipart;
private String filePath;
private int maxFileSize = 50 * 1024;
private int maxMemSize = 10 * 1024;
private File file ;
/* public void init( ){
// Get the file location where it would be stored.
filePath =
getServletContext().getInitParameter("file-upload");
}*/
@Override
public void doPost(HttpServletRequest req, HttpServletResponse res)throws ServletException, java.io.IOException {
// Check that we have a file upload request
java.io.PrintWriter out = res.getWriter( );
// out.println("entered");
isMultipart = ServletFileUpload.isMultipartContent(req);
res.setContentType("text/html");
if( !isMultipart ){
out.println("!multipart");
System.out.println("here");
return;
}
DiskFileItemFactory factory = new DiskFileItemFactory();
// maximum size that will be stored in memory
factory.setSizeThreshold(maxMemSize);
// Location to save data that is larger than maxMemSize.
factory.setRepository(new File("c:/temp"));
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
// maximum file size to be uploaded.
upload.setSizeMax( maxFileSize );
ServletContext servletContext = getServletContext();
String path = servletContext.getRealPath("/");
BufferedReader br=null;
String fileName="";
DBConn db = new DBConn();
try{
// Parse the request to get file items.
System.out.println("here1"+req);
List fileItems = upload.parseRequest(req);
// Process the uploaded file items
Iterator i = fileItems.iterator();
/* out.println("<html>");
out.println("<head>");
out.println("<title>Upload</title>");
out.println("</head>");
out.println("<body>");*/
while ( i.hasNext () )
{
FileItem fi = (FileItem)i.next();
if ( !fi.isFormField () )
{
// Get the uploaded file parameters
String fieldName = fi.getFieldName();
fileName = fi.getName();
String contentType = fi.getContentType();
boolean isInMemory = fi.isInMemory();
long sizeInBytes = fi.getSize();
// Write the file
if( fileName.lastIndexOf("\\") >= 0 ){
file = new File( "c:/Temp/" +
fileName.substring( fileName.lastIndexOf("\\"))) ;
}else{
file = new File( "c:/Temp/"+
fileName.substring(fileName.lastIndexOf("\\")+1)) ;
}
if(!file.exists())
{
File fold=new File(file.getParent());
fold.mkdirs();
}
fi.write( file ) ;
System.out.println("Uploaded Filename: " + fileName + "<br>");
}
}
}catch(Exception ce)
{
out.println("<font size='30' color='red'>Error Code 016</font>");
//out.println("Exception1: "+ce);
}
//read uploaded file and insert into table********************************************
// String newline = System.getProperty("line.separator");
// File file = new File(path+"//"+fileName);
// file.createNewFile();
try{
if(file.isFile())
{
br = new BufferedReader(new FileReader(file));
String str="";
String temp[]=null;
file.canWrite();
file.canRead();
file.setWritable(true);
db.conn.setAutoCommit(false);
while((str=br.readLine())!=null)
{
temp=str.split(" ");
// PreparedStatement ps = db.conn.prepareStatement("INSERT INTO file_proc VALUES(?,?,?,?,?,?,?,?,?,STR_TO_DATE(?,'%m/%d/%Y'))");
PreparedStatement ps = db.conn.prepareStatement("INSERT INTO file_proc(run_date,zone,location,bank,file_type,num_rec,ex_sett_date,ex_stat_date) "
+ "VALUES(STR_TO_DATE(?,'%m/%d/%Y'),?,?,?,?,?,STR_TO_DATE(?,'%m/%d/%Y'),STR_TO_DATE(?,'%m/%d/%Y'))");
ps.setString(1,temp[0]);
ps.setString(2,temp[1]);
ps.setString(3,temp[2]);
ps.setString(4,temp[3]);
ps.setString(5,temp[4]);
ps.setInt(6,Integer.parseInt(temp[5]));
ps.setString(7,temp[6]);
ps.setString(8,temp[7]);
ps.executeUpdate();
ps.close();
}
db.conn.commit();
db.conn.setAutoCommit(true);
db.conn.close();
br.close();
file.delete();
// RequestDispatcher rd = req.getRequestDispatcher("./status/status.jsp");
// rd.forward(req, res);
out.print("success");
// out.println("</html>");
}
else
{
out.println(file+" is not a file");
}
}catch(Exception ex) {
out.println("file name= "+fileName);
// out.println("DBEX= "+ex );
out.println("<font size='30' color='red'>Error Code 017 - Recommended date format = m/d/yyyy.</font>");
out.println("<font size='30' color='red'>Check the column order</font>"+ex);
//file.delete();
// RequestDispatcher rd = req.getRequestDispatcher("./status/error.jsp");
// rd.forward(req, res);
}finally{
try{
db.conn.close();
br.close();
}catch(Exception e){}
}
}
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, java.io.IOException {
doPost(request, response);
}
}
** * *這是表格* ** * **
<form name="file_proc" id="file_proc" method = "post" action="../file_upld" enctype="multipart/form-data">
<br/><br/><br/><br/>
<p align="center">
<input type="file" id="file" name="file" size="50" /><br/>
<br/>
<input type="submit" class="buttons" value="Upload File" />br/><br/><br/>
</p>
</form>
上傳控制器代碼......
package file_proc;
import DBConn.DBConn;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.sql.PreparedStatement;
import java.util.Iterator;
import java.util.List;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
@WebServlet(name="file_upld", urlPatterns = {"/file_upld"})
public class file_upld extends HttpServlet {
private boolean isMultipart;
private String filePath;
private int maxFileSize = 50 * 1024;
private int maxMemSize = 10 * 1024;
private File file ;
/* public void init( ){
// Get the file location where it would be stored.
filePath =
getServletContext().getInitParameter("file-upload");
}*/
@Override
public void doPost(HttpServletRequest req, HttpServletResponse res)throws ServletException, java.io.IOException {
// Check that we have a file upload request
java.io.PrintWriter out = res.getWriter( );
// out.println("entered");
isMultipart = ServletFileUpload.isMultipartContent(req);
res.setContentType("text/html");
if( !isMultipart ){
out.println("!multipart");
System.out.println("here");
return;
}
DiskFileItemFactory factory = new DiskFileItemFactory();
// maximum size that will be stored in memory
factory.setSizeThreshold(maxMemSize);
// Location to save data that is larger than maxMemSize.
factory.setRepository(new File("c:/temp"));
// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);
// maximum file size to be uploaded.
upload.setSizeMax( maxFileSize );
ServletContext servletContext = getServletContext();
String path = servletContext.getRealPath("/");
BufferedReader br=null;
String fileName="";
DBConn db = new DBConn();
try{
// Parse the request to get file items.
System.out.println("here1"+req);
List fileItems = upload.parseRequest(req);
// Process the uploaded file items
Iterator i = fileItems.iterator();
/* out.println("<html>");
out.println("<head>");
out.println("<title>Upload</title>");
out.println("</head>");
out.println("<body>");*/
while ( i.hasNext () )
{
FileItem fi = (FileItem)i.next();
if ( !fi.isFormField () )
{
// Get the uploaded file parameters
String fieldName = fi.getFieldName();
fileName = fi.getName();
String contentType = fi.getContentType();
boolean isInMemory = fi.isInMemory();
long sizeInBytes = fi.getSize();
// Write the file
if( fileName.lastIndexOf("\\") >= 0 ){
file = new File( "c:/Temp/" +
fileName.substring( fileName.lastIndexOf("\\"))) ;
}else{
file = new File( "c:/Temp/"+
fileName.substring(fileName.lastIndexOf("\\")+1)) ;
}
if(!file.exists())
{
File fold=new File(file.getParent());
fold.mkdirs();
}
fi.write( file ) ;
System.out.println("Uploaded Filename: " + fileName + "<br>");
}
}
}catch(Exception ce)
{
out.println("<font size='30' color='red'>Error Code 016</font>");
//out.println("Exception1: "+ce);
}
//read uploaded file and insert into table********************************************
// String newline = System.getProperty("line.separator");
// File file = new File(path+"//"+fileName);
// file.createNewFile();
try{
if(file.isFile())
{
br = new BufferedReader(new FileReader(file));
String str="";
String temp[]=null;
file.canWrite();
file.canRead();
file.setWritable(true);
db.conn.setAutoCommit(false);
while((str=br.readLine())!=null)
{
temp=str.split(" ");
// PreparedStatement ps = db.conn.prepareStatement("INSERT INTO file_proc VALUES(?,?,?,?,?,?,?,?,?,STR_TO_DATE(?,'%m/%d/%Y'))");
PreparedStatement ps = db.conn.prepareStatement("INSERT INTO file_proc(run_date,zone,location,bank,file_type,num_rec,ex_sett_date,ex_stat_date) "
+ "VALUES(STR_TO_DATE(?,'%m/%d/%Y'),?,?,?,?,?,STR_TO_DATE(?,'%m/%d/%Y'),STR_TO_DATE(?,'%m/%d/%Y'))");
ps.setString(1,temp[0]);
ps.setString(2,temp[1]);
ps.setString(3,temp[2]);
ps.setString(4,temp[3]);
ps.setString(5,temp[4]);
ps.setInt(6,Integer.parseInt(temp[5]));
ps.setString(7,temp[6]);
ps.setString(8,temp[7]);
ps.executeUpdate();
ps.close();
}
db.conn.commit();
db.conn.setAutoCommit(true);
db.conn.close();
br.close();
file.delete();
// RequestDispatcher rd = req.getRequestDispatcher("./status/status.jsp");
// rd.forward(req, res);
out.print("success");
// out.println("</html>");
}
else
{
out.println(file+" is not a file");
}
}catch(Exception ex) {
out.println("file name= "+fileName);
// out.println("DBEX= "+ex );
out.println("<font size='30' color='red'>Error Code 017 - Recommended date format = m/d/yyyy.</font>");
out.println("<font size='30' color='red'>Check the column order</font>"+ex);
//file.delete();
// RequestDispatcher rd = req.getRequestDispatcher("./status/error.jsp");
// rd.forward(req, res);
}finally{
try{
db.conn.close();
br.close();
}catch(Exception e){}
}
}
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, java.io.IOException {
doPost(request, response);
}
}
** * *這是表格* ** * **
<form name="file_proc" id="file_proc" method = "post" action="../file_upld" enctype="multipart/form-data">
<br/><br/><br/><br/>
<p align="center">
<input type="file" id="file" name="file" size="50" /><br/>
<br/>
<input type="submit" class="buttons" value="Upload File" />br/><br/><br/>
</p>
</form>
這是log4j的東西，它顯示了filter.java中的錯誤，我沒有在當前的servlet中使用它。
[錯誤] 29:05（file_upld.java:doPost:172）失敗了！
java.lang.NullPointerException在file_proc.file_upld.doPost（file_upld.java:120）的javax.servlet.http.HttpServlet.service（HttpServlet.java:641）javax.servlet.http.HttpServlet.service（HttpServlet.java： 722）atg.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:305）atg.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:210）at filter.filter.doFilter（filter.java ：16）org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:243）org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:210）org.apache.catalina.core。 StandardWrapperValve.invoke（StandardWrapperValve.java:225）位於org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:169）org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:472）org org.apache.ca上的.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:168） 位於org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927）的talina.valves.ErrorReportValve.invoke（ErrorReportValve.java:98）org.apache.catalina.core.StandardEngineValve.invoke（StandardEngineValve.java： 118）org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:407）org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:999）at org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler .process（AbstractProtocol.java:565）atg.apache.tomcat.util.net.JIoEndpoint $ SocketProcessor.run（JIoEndpoint.java:307）at java.util.concurrent.ThreadPoolExecutor.runWorker（ThreadPoolExecutor.java:1110）at at Java.util.concurrent.ThreadPoolExecutor $ Worker.run（ThreadPoolExecutor.java:603）at java.lang.Thread.run（Thread.java:722）
這里是filter.javapackage過濾器;
import java.io.IOException;
import javax.servlet.*;
import javax.servlet.http.HttpServletResponse;
public class filter implements Filter{
private FilterConfig config=null;
@Override
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException
{
HttpServletResponse hsr = (HttpServletResponse) res;
hsr.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.
hsr.setHeader("Pragma", "no-cache"); // HTTP 1.0.
hsr.setDateHeader("Expires", 0); // Proxies.
chain.doFilter(req, res);
}
@Override
public void destroy() { }
@Override
public void init(FilterConfig config) {
this.config = config;
}
}
1 個解決方案
解決方案1
3 已采納 2012-10-11 19:53:42
您的具體問題是由錯誤的異常處理和與控制器的緊耦合視圖引起的。
過濾代碼中的噪音后，大致如下：
File file = null;
try {
// ...
file = new File(...);
// ...
} catch (Exception e) {
out.println("...");
}
try {
if (file.isFile())
// ...
} else {
// ...
}
} catch (Exception e) {
out.println("...");
}
在if (file.isFile())塊的行中拋出了NullPointerException 。 這意味着第一個try塊引發了異常，因此將file保留為null 。
問題的原因有兩方面：
- 第一個
try塊在異常時沒有從servlet方法返回，而是錯誤地繼續代碼流。 - 如果
file不為null則第二個try塊不會事先檢查。
然而，你的具體問題要大得多。 您完全吞下異常並打印不相關的HTML代碼，而不是拋棄它們和/或記錄異常。
替換您的catch塊如下：
} catch (Exception e) {
throw new ServletException(e);
}
默認情況下，這種異常將被記錄並在HTTP 500錯誤頁面中以堆棧跟蹤的形式顯示其完整的榮耀。 堆棧跟蹤為您提供了豐富的信息，以便了解問題並進行修復。
與具體問題無關 ，代碼中存在許多其他概念和設計錯誤，但到目前為止它們與具體問題沒有直接關系。 但是我會建議暫停並仔細閱讀一些理智的Servlet書籍/教程/資源。 這段代碼似乎只是根據Google中的代碼段拼湊而成，而不是經過深思熟慮。 第一步是了解servlet的實際工作方式： servlet如何工作？ 實例化，會話，共享變量和多線程
apache.commons.fileupload引發MalformedStreamException
[英]apache.commons.fileupload throws MalformedStreamException
java.lang.ClassNotFoundException：org.apache.commons.fileupload.FileItemFactory
[英]java.lang.ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory
java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory
[英]java.lang.NoClassDefFoundError: org/apache/commons/fileupload/FileItemFactory
apache commons-fileupload是否總是必須寫入磁盤？
[英]Does apache commons-fileupload always have to write to disk?
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