com.github.jarvisframework.tool.http.FileItem Maven / Gradle / Ivy
package com.github.jarvisframework.tool.http;
import java.io.*;
/**
* 文件包装类 ， 支持本地文件 、 字节数组和输入流三种方式 。
*
* @author Doug Wang
* @date 2019-11-26 09:50:25
*/
public class FileItem {
private Contract contract;
/**
* 基于本地文件的构造器，适用于上传本地文件。
*
* @param file 本地文件
*/
public FileItem(final File file) {
this.contract = new LocalContract(file);
}
/**
* 基于文件绝对路径的构造器，适用于上传本地文件。
*
* @param filePath 文件绝对路径
*/
public FileItem(String filePath) {
this(new File(filePath));
}
/**
* 基于文件名和字节数组的构造器。
*
* @param fileName 文件名
* @param content 文件字节数组
*/
public FileItem(String fileName, byte[] content) {
this(fileName, content, null);
}
/**
* 基于文件名、字节数组和媒体类型的构造器。
*
* @param fileName 文件名
* @param content 文件字节数组
* @param mimeType 媒体类型，如：image/jpeg, text/plain
*/
public FileItem(String fileName, byte[] content, String mimeType) {
this.contract = new ByteArrayContract(fileName, content, mimeType);
}
/**
* 基于文件名和字节流的构造器，适应于全流式上传，减少本地内存开销。
*
* @param fileName 文件名
* @param stream 文件字节流
*/
public FileItem(String fileName, InputStream stream) {
this(fileName, stream, null);
}
/**
* 基于文件名、字节流和媒体类型的构造器，适应于全流式上传，减少本地内存开销。
*
* @param fileName 文件名
* @param stream 文件字节流
* @param mimeType 媒体类型，如：image/jpeg, text/plain
*/
public FileItem(String fileName, InputStream stream, String mimeType) {
this.contract = new StreamContract(fileName, stream, mimeType);
}
public boolean isValid() {
return this.contract.isValid();
}
public String getFileName() {
return this.contract.getFileName();
}
public String getMimeType() throws IOException {
return this.contract.getMimeType();
}
public long getFileLength() {
return this.contract.getFileLength();
}
public void write(OutputStream output) throws IOException {
this.contract.write(output);
}
private static interface Contract {
boolean isValid();
String getFileName();
String getMimeType();
long getFileLength();
void write(OutputStream output) throws IOException;
}
private static class LocalContract implements Contract {
private File file;
public LocalContract(File file) {
this.file = file;
}
@Override
public boolean isValid() {
return this.file != null && this.file.exists() && this.file.isFile();
}
@Override
public String getFileName() {
return this.file.getName();
}
@Override
public String getMimeType() {
return "application/octet-stream";
}
@Override
public long getFileLength() {
return this.file.length();
}
@Override
public void write(OutputStream output) throws IOException {
InputStream input = null;
try {
input = new FileInputStream(this.file);
byte[] buffer = new byte[1024 * 4];
int n;
while (-1 != (n = input.read(buffer))) {
output.write(buffer, 0, n);
}
} finally {
if (input != null) {
input.close();
}
}
}
}
private static class ByteArrayContract implements Contract {
private String fileName;
private byte[] content;
private String mimeType;
public ByteArrayContract(String fileName, byte[] content, String mimeType) {
this.fileName = fileName;
this.content = content;
this.mimeType = mimeType;
}
@Override
public boolean isValid() {
return this.content != null && this.fileName != null;
}
@Override
public String getFileName() {
return this.fileName;
}
@Override
public String getMimeType() {
if (this.mimeType == null) {
return "application/octet-stream";
} else {
return this.mimeType;
}
}
@Override
public long getFileLength() {
return this.content.length;
}
@Override
public void write(OutputStream output) throws IOException {
output.write(this.content);
}
}
private static class StreamContract implements Contract {
private String fileName;
private InputStream stream;
private String mimeType;
public StreamContract(String fileName, InputStream stream, String mimeType) {
this.fileName = fileName;
this.stream = stream;
this.mimeType = mimeType;
}
@Override
public boolean isValid() {
return this.stream != null && this.fileName != null;
}
@Override
public String getFileName() {
return this.fileName;
}
@Override
public String getMimeType() {
if (this.mimeType == null) {
return "application/octet-stream";
} else {
return this.mimeType;
}
}
@Override
public long getFileLength() {
return 0L;
}
@Override
public void write(OutputStream output) throws IOException {
try {
byte[] buffer = new byte[1024 * 4];
int n;
while (-1 != (n = stream.read(buffer))) {
output.write(buffer, 0, n);
}
} finally {
if (stream != null) {
stream.close();
}
}
}
}
}