http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 1rLK1X
} yrVk$k#6}
for(int i=0;i<nEndPos.length-1;i++) (AI 4a+
{ A5[iFT>
nEndPos = nStartPos[i+1]; Z_.xglq{
} V>Vu)7
nEndPos[nEndPos.length-1] = nFileLength; 6(0ME$
} JULns#tx}
} e"O c
+l)[A{
l1I\khS
//启动子线程 UHT2a9rG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [ qx[ 0
for(int i=0;i<nStartPos.length;i++) 'YTSakNJ}
{ x^]J^L45
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x@*!MC#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x=%wPVJ
nStartPos,nEndPos,i); D(&XmC[\Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >#Ue`)d`aY
fileSplitterFetch.start(); f5o##ia7:
} &6q67
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %-J}m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &cHA xker
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .TpM3b#r
nEndPos = " + nFileLength); fx3oA}
// fileSplitterFetch[nPos.length-1].start(); >o,l/#z
wMvAm%}+
'}BYMEd/m%
//等待子线程结束 }LTyXo
//int count = 0; GMW,+
//是否结束while循环 ;*[oi
boolean breakWhile = false; tx_h1[qi
M>g%wg7Ah
eB2a1<S&@
while(!bStop) .6HHUy
{ 8ZL9>"%l
write_nPos(); -ztgirU
Utility.sleep(500); gPqdl6#c
breakWhile = true; E@[ZwTnJ
NSkIzaNY
%ki^XB86
for(int i=0;i<nStartPos.length;i++) >&`;@ZOH
{ Tx:S{n7&
if(!fileSplitterFetch.bDownOver) 'Hv=\p4$1
{ Z%$tV3a?
breakWhile = false; :[d*
break; "rU 2g
} 2`P=ekF]
} !Y^3%B%
if(breakWhile) `RHhc{
break; Q|7l!YTzVu
#fT<]j(
Gc*p%2c
//count++; :sA$LNj}
//if(count>4) wrm ReT?
// siteStop(); D/&nEMp6
} G3${\'<
05s{Z.aK
&e)V!o@wJV
System.err.println("文件下载结束！"); u{8:VX
} [DD#YL\P
catch(Exception e){e.printStackTrace ();} u#)ARCx,w
} 5fY7[{2
y134m
OOZxs?pR
//获得文件长度 ;i-<dAV8B
public long getFileSize() 'bn$"A"{o
{ 0HPqoen$
int nFileLength = -1; *IQQsfL)
try{ uy rS6e0
URL url = new URL(siteInfoBean.getSSiteURL()); ?.Lq`~T`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p5`={'>-
httpConnection.setRequestProperty("User-Agent","NetFox"); #u/5 nm
LXS)(-&
t7 +U!
int responseCode=httpConnection.getResponseCode(); OJT%?P%@{
if(responseCode>=400) Ef\&3TcQ
{ ~%!"!Z4
processErrorCode(responseCode); YckLz01jh
return -2; //-2 represent access is error "'*Qq@!3?
} xz3|m _)
bx:j`5Uj`
FO{?Z%& ;
String sHeader; @&f~#Xe
.f-s+J&ED
|Ng}ZLBM
for(int i=1;;i++) "5@\"L
{ SQ-CdpT<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e'T|5I0K
//Utility.log(in.readLine()); 8;$zD]{D1
sHeader=httpConnection.getHeaderFieldKey(i); d8J(~$tXQN
if(sHeader!=null) SYA0Hiw7P
{ !`0 El',gY
if(sHeader.equals("Content-Length")) cCv@fks
{ tqXCj}mR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1eOQ;#OV
break; j2s{rQQ
} ",pd 9
} JYrOE"!h
else +wGFJLHJ
break; go?}M]c%7
} Vc!'=&*
} J[al4e^
catch(IOException e){e.printStackTrace ();} _18Aek
catch(Exception e){e.printStackTrace ();} @*=eqO
AHet,N
[z,6K=
Utility.log(nFileLength); h3j`X'
<Y)Aez
0?*":o30
return nFileLength; ~(}nd
} D-Q54"^3
Zp+orc7
9`cj9zz7
//保存下载信息（文件指针位置） VJS1{n=;k
private void write_nPos() ~\u~>mtchu
{ />O.U?
try{ =8AL>:_
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,U.|+i{
output.writeInt(nStartPos.length); /mwsF]Y
for(int i=0;i<nStartPos.length;i++) ^%NjdZuDO
{ jdd3[
// output.writeLong(nPos); z-m:l;
output.writeLong(fileSplitterFetch.nStartPos); 7ZFd;-
output.writeLong(fileSplitterFetch.nEndPos); ne# %Gr
} GpXU&A'r
output.close(); zKFiCP K
} TNlS2b1
catch(IOException e){e.printStackTrace ();} &H/3@A3
catch(Exception e){e.printStackTrace ();} @5{h+^
} E&0]s
Q&vU|y
:oytJhxU
//读取保存的下载信息（文件指针位置） &{S@v9~IT
private void read_nPos() C,$7fW{?
{ wLKC6@ W
try{ <*z9:jzQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $.O(K4S
int nCount = input.readInt(); * & : J
nStartPos = new long[nCount]; s[%@3bY!7
nEndPos = new long[nCount]; h%&2M58:
for(int i=0;i<nStartPos.length;i++) m0]Lc{
{ 8xx2+
nStartPos = input.readLong(); $u, ~183
nEndPos = input.readLong(); T1uOp5_]B
} @gi / 1cq
input.close(); 86W.z6
} JPq' C$
catch(IOException e){e.printStackTrace ();} ,@aF#
catch(Exception e){e.printStackTrace ();} ><{Lh@{
} g3c,x kaO
Bs\&'=l
A[H"(E#k
private void processErrorCode(int nErrorCode) D:XjJMW3r
{ 2[1lwV
System.err.println("Error Code : " + nErrorCode); R2y~+tko?
} RC^k#+
i*e'eZ;)
\1oN't.
//停止文件下载 "T.Qb/97@
public void siteStop() CUx[LZR7m
{ @|fT%Rwho<
bStop = true; sK7b4gmK
for(int i=0;i<nStartPos.length;i++) ):nC&M\W~
fileSplitterFetch.splitterStop(); lz(}N7SLa
^@;P-0Sy
T_oL/x_;
} ?:#$btmn?
} K*N8Vpz(
//负责部分文件的抓取 '19kP.
**FileSplitterFetch.java oI x!?,1
*/ Xd'B0kQaT
package NetFox; 0(+dXzcwM
~/;shs<9EM
8xYeaK
import java.io.*; }M &hcw<
import java.net.*; 8)="Ee
,ZvlKN
9O-*iK
public class FileSplitterFetch extends Thread { .>^U mM
59k-,lyU,
qwYq9A$+
String sURL; //File URL gk4DoOj#P
long nStartPos; //File Snippet Start Position PGA `R
long nEndPos; //File Snippet End Position 43N=OFU
int nThreadID; //Thread's ID I GB)
boolean bDownOver = false; //Downing is over hc]5f3Z
boolean bStop = false; //Stop identical S=X_7V
FileAccessI fileAccessI = null; //File Access interface A&:~dZ:%w
VX e7b
0yL%Pjn6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7 '{wl,u
{ 9Nu:{_YoP
this.sURL = sURL; DpQ:U5j
this.nStartPos = nStart; 1p(9hVA
this.nEndPos = nEnd; X,`e1nsR
nThreadID = id; _OJ19Ry
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1qhSN#s{_
} TTz_w-68
nh>lDfJV<
$%"~.L4
public void run() =5#sB*
{ MzIn~[\
while(nStartPos < nEndPos && !bStop) n4 J*04K
{ 'Jl73#3
90!67Ap`x
E~1"Nh
try{ .<.#g+
URL url = new URL(sURL); Vn6]h|vm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^qV6khg
httpConnection.setRequestProperty("User-Agent","NetFox"); ^zR*s |1Q
String sProperty = "bytes="+nStartPos+"-"; h2vD*W
httpConnection.setRequestProperty("RANGE",sProperty); >\Ml\CyL
Utility.log(sProperty); lM[FT=M
M[?0 ^ FBx
myDcr|j-a
InputStream input = httpConnection.getInputStream(); ^(1S`z$
//logResponseHead(httpConnection); io*iA<@Gx
BS+=*3J
n!%'%%o2v
byte[] b = new byte[1024]; QP!0I01
int nRead; $'Qv {
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "i;"
{ ^MUvd
nStartPos += fileAccessI.write(b,0,nRead); l6< bV#_qe
//if(nThreadID == 1) }Bn`0;]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d8M8O3
} OLyl.#J
zC_@wMWB
VU\{<j{
Utility.log("Thread " + nThreadID + " is over!"); JI|MR#_u
bDownOver = true; sjwD x0(7=
//nPos = fileAccessI.write (b,0,nRead); YY 8vhnw
} $;B0x
catch(Exception e){e.printStackTrace ();} f}VIkx]X"
} .@3bz
} ++Fk8R/$U[
/@+[D{_Fw
@;h$!w<
//打印回应的头信息 YB"=eld
public void logResponseHead(HttpURLConnection con) qp55U*
{ c_FnJ_++f
for(int i=1;;i++) ]?(_}""1
{ [M&.'X
String header=con.getHeaderFieldKey(i); 0i/!nke.
if(header!=null) "i~~Q'=7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i|QL6e*0
Utility.log(header+" : "+con.getHeaderField(header)); >2dF^cDE-3
else L<_zQ
break; :x36Z4:
} `E-cf7%
} 's 'H&sa
{}N=pL8MS
i[m-&
public void splitterStop() y~;w`5;|
{ ::2(pgH
bStop = true; SX@zDuM
} @V qI+5TA
@&GfCg5Cb
.0iHI3i^
} |ZJ<N\\h-
%)!b254
AIw<5lW
/* qfsu# R
**FileAccess.java ^ 9FRI9?
*//文件访问(定位，写) fm&pxQjg
package NetFox; H:_R[u4r
import java.io.*; % n~ 'UA
DE" Y(;S
Jj,fdP#\
public class FileAccessI implements Serializable{ jxTYW)E
=w2_1F"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QV9z81[
RandomAccessFile oSavedFile; ":V,&o9n
long nPos; @szr '&\%A
\cW9"e'
52#Ac;Y
public FileAccessI() throws IOException zt/N)5\V
{ c@/K}
this("",0); ?"L ^0%
} 2^4OaHY88
#D|n6[Y'.t
6uKS!\EY|
public FileAccessI(String sName,long nPos) throws IOException feG#*m2g
{ =9L1Z \f
oSavedFile = new RandomAccessFile(sName,"rw"); %)p?&_
this.nPos = nPos; xDEjeM G
oSavedFile.seek(nPos); EiCEB;*z|d
} ^!sIEL
bW^JR,
gt)wk93d>
public synchronized int write(byte[] b,int nStart,int nLen) ky=h7#wdv-
{ !?5YXI,
int n = -1; }B@44HdY
try{ Am"e%|:
oSavedFile.write(b,nStart,nLen); 2+cpNk$
n = nLen; 'ocPG.PaU
} B\Uocn
catch(IOException e) Z,7VOf6g
{ !8OgaMngzF
e.printStackTrace (); hD9b2KZv
} ciGJtD&P
(0u(<qA\
jj6yf.r6c
return n; 7mtX/w9
} RJOW#e :
9A ?)n<3d
:s>x~t8g#n
} BV=~!tsl
y7| 3]>Z
6os{q`/Q])
/* cV:Ak~PKl
**SiteInfoBean.java DIF-%X5
*/ frT<9$QUL
package NetFox; #eIFRNRb)
~|( eh9
OTzuOP8
public class SiteInfoBean { #*X\pjZ
-{A*`.[v
Fs&r^ [/b
private String sSiteURL; //Site's URL f"SK3hI$p
private String sFilePath; //Saved File's Path CN:z *g
private String sFileName; //Saved File's Name 3<HZ)w^B
private int nSplitter; //Count of Splited Downloading File OJ r~iUr
sW@_' Lw
n&3}F?
public SiteInfoBean() ZdgzPs"
{//nSplitter的缺省值为5 tmi)LRF H
//default value of nSplitter is 5 }CL7h;5N 3
this("","","",5); ZlP+t>
} 8kT`5`}lB
7=gcdfW,;x
!RSJb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p0hE`!
{ Lg{M<Q)4
sSiteURL= sURL; -\n%K
sFilePath = sPath; 5bBCI\&sam
sFileName = sName; :l&Yq!5
this.nSplitter = nSpiltter; f+1@mGt
6ZfL-E{
[0vqm:P
} +QNsI2t;r
8Qhj_
.wB'"z8L
public String getSSiteURL() 9{ #5~WP
{ mM:%-I\$
return sSiteURL; h"nhDART<
} 3g3f87[
AEkjyh\
V-eRGSx
public void setSSiteURL(String value) 5Dzf[V^]`
{ voQJ!h1
sSiteURL = value; No`*->R
} mm;sf
zK&1ti@wln
v3]5`&3~
public String getSFilePath() \&b 9
{ TD%&9$F
return sFilePath; )ZI#F]
} bi^Pk,'
`][vaLd`Q
u /]P
public void setSFilePath(String value) %-a;HGbZn
{ *V4%&&{
sFilePath = value; @yo6w}3+-
} ==Xy'n9'
N`?|~g3
U8J9 #+:
public String getSFileName() (T%?@'\
{ b$yIM
return sFileName; b.v +5=)B
} uVKe?~RC
S~)`{ \
<bb!BS&w
public void setSFileName(String value) ?|98Y"w
{ 3n)$\aBE
sFileName = value; ,n[<[tkCR
} 6<T:B[a-
~M8|r!_
Arm'0)B>
public int getNSplitter() ;i\N!T{>
{ oyr b.lu/
return nSplitter; (xHu@l!]
} ;mT}Q;F#
^lt2,x
Vjs'|%P7
public void setNSplitter(int nCount) S3l^h4
{ _cE_\Ay
nSplitter = nCount; QS!Z*vG
} jU~ x^Y
} v/9DD%An
?_d6;
qB (Pqv
/* a6j& po
**Utility.java 3>^]r jFw
*/ =Y81h-
package NetFox; B}[f]8jrM
HE-5e): k
ZnRT$ l O
public class Utility { '~Cn+xf4]
cM3B5Lp
M:GpyE%
public Utility() !u@P\8M}
{ NIVR;gm
z?.9)T9_
Vj9X6u}{
} A5J41yH
g i6s+2
//线程睡眠 #Zw:&' QB
public static void sleep(int nSecond) JJ7A` ;
{ x<M::")5!V
try{ ^;<d<V}*
Thread.sleep(nSecond); bf0,3~G,P
} D<d,9S,)
catch(Exception e) j :B/ FL
{ &`@YdZtd"
e.printStackTrace (); &TBFt;
} Mq)]2>"v
} 6"* <0
Q;8z&4s@
//日志 p$9Aadi]
public static void log(String sMsg) k:Y\i]#yP
{ lQ`=PFh
System.err.println(sMsg); (&Rk#iU 2
} (Fon!_$:
M%`CzCL u
mdEJ'];AH
public static void log(int sMsg) 3?a`@C&x
{ ?&#LmeZ}K
System.err.println(sMsg); IZj`*M%3
} ,{HQKHg
} .)b<cH~%
v,ZYh w
&L$9Ii
/* __'4Qt
**TestMethod.java r[i^tIv6As
*/ 7/IL" D
package NetFox; (l^7EpNs
&]o-ZZX
]}!@'+=
public class TestMethod { NplyvjQN;
\L(cFjLIl
!vAmjjB
public TestMethod() e9{0hw7
{ ///xx/weblogic60b2_win.exe E+O{^C=
try{ ~dr,;NhOLJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #j~FlY5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dYrgL3'
SiteFileFetch fileFetch = new SiteFileFetch(bean); lf7bx}P*
fileFetch.start(); bwXeEA@{
} RH;ulAD6(~
catch(Exception e){e.printStackTrace ();} 4n1g4c-
CVa>5vt
ad: qOm
} ~gd#cL%
>NBc-DX^
88osWo6rG
public static void main(String[] args) -j3Lgm
{ a ~v$ bNu
new TestMethod(); PK2;Ywk`
} =:s`C,l.4
} {h+8^
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