Http Server 文件下载与上传，form表单字节码解析_文件传输 字节码 表单-CSDN博客
package com.feng.server.http;
import com.sun.net.httpserver.Headers;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
public class HttpRequestFormResolver {
private static final int PARAM_INDEX = "Content-Disposition: form-data; ".length();
public static List<ParamItem> resolveForm(Headers headers, byte[] body) throws IOException {
String contentType = headers.getFirst("Content-type");
String boundary = contentType.substring(contentType.indexOf("=") + 1);
boundary = "--" + boundary; //size 52
byte[] boundaryBytes = boundary.getBytes(StandardCharsets.UTF_8);
List<ParamItem> paramItems = new LinkedList<>();
List<Integer> boundaryIndex = boundaryIndex(body, boundaryBytes);
int paramSize = boundaryIndex.size() - 1;
int boundaryLen = boundaryBytes.length;
byte[] sep = "\r\n".getBytes(StandardCharsets.UTF_8);
for (int i = 0; i < paramSize; i++) {
ParamItem paramItem = resolveParam(body, boundaryIndex.get(i)+boundaryLen+2, boundaryIndex.get(i+1), sep);
paramItems.add(paramItem);
}
return paramItems;
}
/**
* 单个参数解析
*/
private static ParamItem resolveParam(byte[] body, int start, int end, byte[] sep) {
int count = 0;
int cursor = start;
ParamItem paramItem = null;
for (int i = start; i < end; i++) {
for (int j = 0; j < 2; j++) {
if (body[i + j] == sep[j]) {
count++;
} else {
break;
}
}
if (count == 2) {
byte[] line = new byte[i-cursor];
System.arraycopy(body, cursor, line, 0,i-cursor);
//参数的key value分隔符 \r\n
if (isLineBlank(line)) {
cursor = i+2;
if (paramItem == null) {
return null;
}
if (paramItem.getType().equals("text")) {
byte[] val = new byte[end - cursor-2];
System.arraycopy(body, cursor, val, 0, end-cursor-2);
paramItem.setVal(new String(val));
} else {
paramItem.setStartIndex(cursor);
paramItem.setEndIndex(end);
}
break;
} else {
String lineStr = new String(line);
if (lineStr.startsWith("Content-Disposition: form-data; ")) {
paramItem = resolveParam(lineStr);
}
cursor = i;
}
i++;
}
count = 0;
}
return paramItem;
}
private static ParamItem resolveParam(String lineStr){
lineStr = lineStr.substring(PARAM_INDEX);
String[] kVs = lineStr.split(";");
ParamItem paramItem = new ParamItem();
paramItem.setType("text");
for (String kV : kVs) {
String[] k_v = kV.trim().split("=");
if ("name".equals(k_v[0])) {
paramItem.setName(k_v[1].replace("\"", ""));
} else if ("filename".equals(k_v[0])) {
paramItem.setFilename(k_v[1].replace("\"", ""));
paramItem.setType("file");
}
}
return paramItem;
}
private static boolean isLineBlank(byte[] line){
if (line.length == 0) {
return true;
}
byte[] sep = "\r\n".getBytes(StandardCharsets.UTF_8);
if (line.length == 2) {
if (line[0] == sep[0] && line[1] == sep[1]) {
return true;
}
}
return false;
}
/**
* 索引参数的index
*/
private static List<Integer> boundaryIndex(byte[] body, byte[] boundary){
int count = 0;
List<Integer> list = new ArrayList<>();
int length = body.length;
int boundaryLen = boundary.length;
for (int i = 0; i < length; i++) {
for (int j = 0; j < boundaryLen; j++) {
if (i + j == length) {
return list;
}
if (body[i + j] == boundary[j]) {
count++;
} else {
break;
}
}
if (count == boundaryLen) {
list.add(i);
i += boundaryLen - 1;
}
count = 0;
}
return list;
}
public static class ParamItem {
private String type;//text file
private String name;
private String filename;
private String val;
private int startIndex;
private int endIndex;
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getFilename() {
return filename;
}
public void setFilename(String filename) {
this.filename = filename;
}
public String getVal() {
return val;
}
public void setVal(String val) {
this.val = val;
}
public int getStartIndex() {
return startIndex;
}
public void setStartIndex(int startIndex) {
this.startIndex = startIndex;
}
public int getEndIndex() {
return endIndex;
}
public void setEndIndex(int endIndex) {
this.endIndex = endIndex;
}
@Override
public String toString() {
return "ParamItem{" +
"type='" + type + '\'' +
", name='" + name + '\'' +
", filename='" + filename + '\'' +
", val='" + val + '\'' +
", startIndex=" + startIndex +
", endIndex=" + endIndex +
'}';
}
}
}