struts2上傳問題

Question

java.lang.NullPointerException
java.io.FileInputStream.<init>(FileInputStream.java:103)
com.struts.action.UploadAction.execute(UploadAction.java:56)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:440)
com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:279)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:242)
com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:163)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:249)
org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:122)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:195)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:148)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:93)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:306)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:89)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:128)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:104)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:267)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:126)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:138)
com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:87)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:148)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:128)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:236)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:468)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:395)
org.apache.struts2.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:102)
UploadAction:public class UploadAction extends ActionSupport { private String username;
private String password;
private File file;

private String fileFileName;
private String fileContentType;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public File getFile() {
return file;
}
public void setFile(File file) {
this.file = file;
}
public String getFileFileName() {
return fileFileName;
}
public void setFileFileName(String fileFileName) {
this.fileFileName = fileFileName;
}
public String getFileContentType() {
return fileContentType;
}
public void setFileContentType(String fileContentType) {
this.fileContentType = fileContentType;
}



public String execute() throws Exception {

InputStream is=new FileInputStream(file);

String root=ServletActionContext.getRequest().getRealPath("/upload");

File destfile=new File(root,this.getFileFileName());
OutputStream os=new FileOutputStream(destfile);
byte[] bt=new byte[400];
int length=0;

while((length = is.read(bt))>0)
{
os.write(bt,length,0);

}

is.close();
os.close();



return SUCCESS;
}

Answer 1

String root=ServletActionContext.getRequest().getRealPath("/upload");
这个方法是被声明过时的啊，怎么还用？？

Answer 2

问题大概出在这里吧
        String root=ServletActionContext.getRequest().getRealPath("/upload");
        
        File destfile=new File(root,this.getFileFileName());
        OutputStream os=new FileOutputStream(destfile);
创建文件失败给你个例子看吧：import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Date;import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionSupport;public class FileUploadAction extends ActionSupport {
private File file;
private String fileFileName;
private String fileContentType;
private String description;
private String uploadDir;

public File getFile() {
return file;
}

public void setFile(File file) {
this.file=file;
}

public String getFileFileName() {
return fileFileName;
}

public void setFileFileName(String fileFileName) {
this.fileFileName=fileFileName;
}

public String getFileContentType() {
return fileContentType;
}

public void setFileContentType(String fileContentType) {
this.fileContentType=fileContentType;
}

public String getDescription() {
return description;
}

public void setDescription(String description) {
this.description=description;
}

public String getUploadDir() {
return uploadDir;
}

public void setUploadDir(String uploadDir) {
this.uploadDir=uploadDir;
}

public String execute() throws Exception {
String newFileName=null;
long now=new Date().getTime();
String path=ServletActionContext.getServletContext().getRealPath(uploadDir);
File dir=new File(path);

if(!dir.exists()) {
dir.mkdir();
}

int index=fileFileName.lastIndexOf(".");

if(index != -1) {
newFileName=now + fileFileName.substring(index);
} else {
newFileName=Long.toString(now);
}

BufferedOutputStream bos=null;
BufferedInputStream bis=null;

try {
FileInputStream fis=new FileInputStream(file);
bis=new BufferedInputStream(fis);

FileOutputStream fos=new FileOutputStream(new File(dir, newFileName));
bos=new BufferedOutputStream(fos);

byte[] buf=new byte[4096];

int len=-1;
while((len=bis.read(buf)) != -1) {
bos.write(buf, 0, len);
}
}

finally {
try {
if(null!=bis) {
bis.close();
}
} catch(IOException e) {
e.printStackTrace();
}

try {
if(null!=bos) {
bos.close();
}
} catch(IOException e) {
e.printStackTrace();
}
}

return SUCCESS;
}
}

Answer 3

是我自己太大意了，我把upload.jsp中的<s:file name="filename" label="filename"/>
而Uploadaction中衹有
 private String username;    private String password;
    private File file;
    
    private String fileFileName;
    private String fileContentType;