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)); Efo,5
} qucw%hJr
for(int i=0;i<nEndPos.length-1;i++) $.Fti-5
{ PVBf'
nEndPos = nStartPos[i+1]; y?BzZ16\bL
} "X/cG9Lw
nEndPos[nEndPos.length-1] = nFileLength; zPwU'TbF
} ['F,
} `V N $ S
"]BefvE
_H#l&bL@C
//启动子线程 )u{)"m`&[J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <.c@l,[.z
for(int i=0;i<nStartPos.length;i++) [kc%+j<g
{ z?C;z7eT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p)M\q fZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~z''kH=e
nStartPos,nEndPos,i); ~r`~I"ZK7^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f@roRn8p?
fileSplitterFetch.start(); XxT7YCi
} Bsm>^zZ`YU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $)OUOv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h'8w<n+%)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7Gb(&'n
nEndPos = " + nFileLength); 0(9]m)e
// fileSplitterFetch[nPos.length-1].start(); N7lWeF
yKR0]6ahA
Pw4j?pv2
//等待子线程结束 p_hljgOV
//int count = 0; t(SSrM]
//是否结束while循环 mPR(4Ol.
boolean breakWhile = false; t >89( k
^/+0L[R
7h?yAgDv~
while(!bStop) r.e,!Bs
{ U].u) g$
write_nPos(); j[/'`1tOe
Utility.sleep(500); m.~&n!1W*`
breakWhile = true; $mA+4ISK
B7Um G)C
h-VpX6
for(int i=0;i<nStartPos.length;i++) z~d\d!u1
{ )r O`K
if(!fileSplitterFetch.bDownOver) 5BKmp-m
{ nU"V@_?\
breakWhile = false; *qcL(] Yq
break; dvUBuY^[
} K`PmWxNPh
} V'h O
if(breakWhile) \FOX#|i)
break; W'{q
l'~]8Wo1
#80*3vi~F
//count++; <DS+"#
//if(count>4) ^iJMUV|
// siteStop(); qlUYu"`i
} 7pNTCZY|
?i4}[q
LkFXUt?
System.err.println("文件下载结束！"); "AjtNL5
} ;S+c<MSl
catch(Exception e){e.printStackTrace ();} `~( P
} kmM4KP#&|
s(7'*`G"h
Fz+0h"
//获得文件长度 ;K?fAspSH
public long getFileSize() Fi{~UOZg
{ 0|X!Uw-Q%_
int nFileLength = -1; 2tvMa%1^
try{ %l@Q&)f8e
URL url = new URL(siteInfoBean.getSSiteURL()); sY,!Ir`/`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;_0)f
httpConnection.setRequestProperty("User-Agent","NetFox"); d#T8|#O"
n<:/ X tE
#)%N+Odnr
int responseCode=httpConnection.getResponseCode(); zOq~?>Ms6
if(responseCode>=400) )>,b>7
{ 4ei .-
processErrorCode(responseCode); F2yM2Ldx
return -2; //-2 represent access is error >Uvtsj#
} ,eRl Z3T
:=04_5 z
8eP2B281
String sHeader; "fLGXbNQ
GK}?*Lfs
z)5n&w S
for(int i=1;;i++) a34'[R
{ $P]%Px!x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); HSx~Fs^J
//Utility.log(in.readLine()); =S@$"_&
sHeader=httpConnection.getHeaderFieldKey(i); kP%W:4l0
if(sHeader!=null) ua:.97~Ym
{ uMF\3T(x4
if(sHeader.equals("Content-Length")) 1$idF
{ B@*BcE?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bl\44VK2'
break; $X5~9s1Wl
} -mZo`
} MAR kTxzi
else l1c&a[M)
break; kETA3(h'
} )iy>sa{
} <Q=ES,M
catch(IOException e){e.printStackTrace ();} ^e8R43w:!
catch(Exception e){e.printStackTrace ();} 5h[u2&;G
P<kTjG
ZP?k|sEH
Utility.log(nFileLength); c}mJ6Pt
#s1M>M)
;JFE7\-mC
return nFileLength; ?9X#{p>q
} c i7;v9
%e7{ke}r
l{#m"S7J^
//保存下载信息（文件指针位置） iCN@G&rVw
private void write_nPos() GMU<$x8o
{ *cp|lW!ag
try{ #2DH_P
output = new DataOutputStream(new FileOutputStream(tmpFile)); L5yxaF{]
output.writeInt(nStartPos.length); N(&FATZUW
for(int i=0;i<nStartPos.length;i++) Nl_!%k:
{ J+\F)k>r
// output.writeLong(nPos); ,@='.Qs4g
output.writeLong(fileSplitterFetch.nStartPos); 8<P$E!
output.writeLong(fileSplitterFetch.nEndPos); 2xe_Q70II
} B\|>i~u(
output.close(); v}zo vEi
} LO.4sO
catch(IOException e){e.printStackTrace ();} T9Vyj3!i_
catch(Exception e){e.printStackTrace ();} j`BFk>
} #2ZXYH}
0&/1{Dk*n
z9HQFRbo[
//读取保存的下载信息（文件指针位置） `1EBnL_1
private void read_nPos() 1`O`!plD+
{ d(wqKiGwe
try{ 'n:Ft
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %~p_bKd~
int nCount = input.readInt(); /F;*[JZIb
nStartPos = new long[nCount]; .F#mT h
nEndPos = new long[nCount]; 9b]U&A$
for(int i=0;i<nStartPos.length;i++) eiEZtu
{ F:pXdU-xf
nStartPos = input.readLong(); 6xL=JSi~
nEndPos = input.readLong(); 0y;&L63>T
} 9,`mH0jP
input.close(); 2+=|!+f
} MVt#n\_BZV
catch(IOException e){e.printStackTrace ();} 0*3 <}
catch(Exception e){e.printStackTrace ();} JF{,;&sj
} 6j"(/X|Ex5
+8^9:w0}
IU$bP#<
private void processErrorCode(int nErrorCode) {'DP/]nK
{ +"3eh1q[
System.err.println("Error Code : " + nErrorCode); |~\K:[T&
} !a~x|pjJ
`zzX2R Je
K+v 250J$-
//停止文件下载 x(]s#D!)
public void siteStop() ~;eWQwD
{ ,xD{A}}V
bStop = true; jLQjv
for(int i=0;i<nStartPos.length;i++) {Y/|7Cl0
fileSplitterFetch.splitterStop(); eU%5CVH.v
TdKl`"Iy
h*MR5qa
} "[[fQpe4@
} tMAa$XrZj
//负责部分文件的抓取 ^<E+7
**FileSplitterFetch.java 9Biw!%a
*/ Dx <IS^>i
package NetFox; ik$wS#1+L
$,aU"'D
=R>Sxaq
import java.io.*; J.<eX=<
import java.net.*; EW5S%Y
,j_{IL690
Y~vTFOI
public class FileSplitterFetch extends Thread { SAH\'v0
5)nv
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String sURL; //File URL )D[ypuM&
long nStartPos; //File Snippet Start Position BB%(!O4Dl
long nEndPos; //File Snippet End Position LpmspIPvf
int nThreadID; //Thread's ID 9d{W/t?NH
boolean bDownOver = false; //Downing is over =k$d8g ez
boolean bStop = false; //Stop identical mr('zpkRq
FileAccessI fileAccessI = null; //File Access interface pRU6jV 6e)
nZ bg
h[Iu_#HMa
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :.35pp,0
{ ("lcL2Bq
this.sURL = sURL; Vbj?:29A
this.nStartPos = nStart; y:42H tS
this.nEndPos = nEnd; '^/E2+
nThreadID = id; xJ"Zg]d{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /ruf1?\,R
} 6~!YEuA
8^R>y
8m1zL[.8g
public void run() > T-O3/KN
{ ,B#Y9[R
while(nStartPos < nEndPos && !bStop) <khx%<)P
{ vlPE8U=
*$cp"
:jUuw:\
try{ YAPD7hA
URL url = new URL(sURL); l?R_wu,Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0l:5hD,)F
httpConnection.setRequestProperty("User-Agent","NetFox"); eXOFAd]>u
String sProperty = "bytes="+nStartPos+"-"; (C3d<a\:
httpConnection.setRequestProperty("RANGE",sProperty); (Dl"s`UH~
Utility.log(sProperty); bv+e'$U3
@[FFYVru
UpIf t=@P
InputStream input = httpConnection.getInputStream(); u}:O[DG
//logResponseHead(httpConnection); XBY"7}
{30<Vc=
CYn}wkz
byte[] b = new byte[1024]; p|FX_4RjX
int nRead; O#EBR<CuK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZGbZu
{ %om7h$D=`
nStartPos += fileAccessI.write(b,0,nRead); E1C8yIF
//if(nThreadID == 1) >WDpBn:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -of= Lp
} ('lnQD.Hd
7 %|>7
<+b:
Utility.log("Thread " + nThreadID + " is over!"); +>3c+h,%.
bDownOver = true; rx;U/)~#<
//nPos = fileAccessI.write (b,0,nRead); X3-1)|g !z
} nB]Q^~jX
catch(Exception e){e.printStackTrace ();} X,N@`
} '" tieew
} d+;wDu
{+[gf:Ev
YHA[PF
//打印回应的头信息 {Psj#.qP1
public void logResponseHead(HttpURLConnection con) \'EWur"
{ !K 9(OX2;
for(int i=1;;i++) y?JbJ
{ yJL"uleRT
String header=con.getHeaderFieldKey(i); p)jxqg
if(header!=null) AFFLnLA<L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }M7kApb>Y
Utility.log(header+" : "+con.getHeaderField(header)); Sy'>JHx
else w7D:0SGD
break; 6,)y{/ENC
} CIDL{i8
} 4eEs_R
&\H5*A.HkA
IYO,/ kbf
public void splitterStop() V[mQ;:=
{ etoE$2c
bStop = true; iN*>Z(b"
} PGKXzp'
1A)~Y
uUe\[-~
} 5ZcnZlOOQ
3k<#;(
[GP(r
/* [o.zar82
**FileAccess.java kYs|")isj
*//文件访问(定位，写) s z\RmX
package NetFox; 16>uD;G
import java.io.*; XZInu5(
PsgzDhRv
#'8PFw\zw
public class FileAccessI implements Serializable{ `Z/IW
nX~MoWH1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -!0LIr:"
RandomAccessFile oSavedFile; vxeT[/6i
long nPos; `Ek!;u>
KVR}Tp/R
)^\='(s
public FileAccessI() throws IOException !{Y#<tG]
{ <J)A_Kx[57
this("",0); 2mUu3fZ
} _}&]`,s>
C6VoOT)\
*r`Yz}
public FileAccessI(String sName,long nPos) throws IOException 9^='&U9sr
{ MuobMD}jqe
oSavedFile = new RandomAccessFile(sName,"rw"); 'oz={;
this.nPos = nPos; YfPo"uxx
oSavedFile.seek(nPos); IR LPUP
} +29\'w,
{h"\JI!
i6d$/yP"
public synchronized int write(byte[] b,int nStart,int nLen) lX*;KHT)
{ swlWe}1
int n = -1; ,}tdfkZFYl
try{ o"FiM5L^.
oSavedFile.write(b,nStart,nLen); Xa@wN/"F
n = nLen; (UF!Zb]{
} Gme$FWa
catch(IOException e) F}]_/cY7B
{ /6?plt&CA
e.printStackTrace (); y!gM)9vq
} j7 =3\SO
LJwMM
M0SH-0T;Z
return n; 358/t/4{p
} Pm^N0L9?q
@;fE%N
~5NGDT#L*
} U 0RfovJ
HF: T]n,
LUNs|\&
/* Wi?%)hur
**SiteInfoBean.java BozK!"R_<
*/ <83gn :$
package NetFox; qb4;l\SfT
c@-K
Zd U{`>v
public class SiteInfoBean { 1Wk EPj,
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^|GtO.
private String sSiteURL; //Site's URL n2mw@Ay!
private String sFilePath; //Saved File's Path ms7 7{A3
private String sFileName; //Saved File's Name %^=!s
private int nSplitter; //Count of Splited Downloading File ocqB-C]
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y,?G75wij
public SiteInfoBean() J md ?
{//nSplitter的缺省值为5 R.H\b!
//default value of nSplitter is 5 *+j{9LK
this("","","",5); 2A}uqaF
} h+3Z.WKhwP
0@K:Tq-mF
loUwRz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ` G=L07
{ )H9*NB8%
sSiteURL= sURL; (oitCIV
sFilePath = sPath; G>,nZ/,A{
sFileName = sName; W)!{U(X
this.nSplitter = nSpiltter; 5@D7/$bLp
$xtE+EV.p
yVI;s|jG
} 7~ese+\smG
DRW.NL o
sV^h#g~Zb
public String getSSiteURL() p/1}>F|i
{ V$<G)dwUG5
return sSiteURL; %?oU{KzQ@;
} 0r-lb[n8i
//M4Sq(
:aq>
public void setSSiteURL(String value) /QXs-T}d
{ aE\BAbD7
sSiteURL = value; ^wF@6e7/&
} Sq|1f?_gU
*_<*bhR<
gn W~KLqH
public String getSFilePath() r.wIk0
{ N9=r#![>,
return sFilePath; 2v9s@k/k)6
} K%c ATA3
U=i8>6V
+Bq}>
public void setSFilePath(String value) g<iwxF
{ 03QEXm~|Q
sFilePath = value; #1't"R+3M
} cCh5Jl@Z
an=+6lIl
7#9'2dI
public String getSFileName() 380->
{ # 5f|1O
return sFileName; (Cl`+ V
} `,-hG
"T a9
LbV]JP
public void setSFileName(String value) %V%#y $l
{ JQ@`EV9,
sFileName = value; 9<A\npD
} v!#`W
B!r48<p
pl#o!j(i
public int getNSplitter() ^wO_b'@v
{ UJz4>JF
return nSplitter; Wl !!5\
} QFNz9c
^?6 W<
t$y&=v
public void setNSplitter(int nCount) q3x;_y^
{ Q}Ze-JIL$
nSplitter = nCount; XJJ[F|k~
} V"7<[u]K|
} < R|)5/9
GIC"-l1\
[^U;
/* pKxX{i1l
**Utility.java y/@;c)1b9
*/ FU5LYXCs
package NetFox; Z9"{f)T
\2R`q*a+
4h;f>BG
public class Utility { {V%%^Zhwy
Q+N7:o!;<b
k,;lyE
public Utility() Pu$kj"|q*[
{ *CH!<VB/
5y(t`Fmt
d(X\B{
} K#l -?
5DkK'tCI9Z
//线程睡眠 . QQ?w
public static void sleep(int nSecond) zL)1^[%O9
{ lTV@b&
try{ o5=)~D{/G3
Thread.sleep(nSecond); NoJnchiU
} uG=t?C6
catch(Exception e) ^J#?hHz
{ ;/?Z<[B
e.printStackTrace (); >}<29Ii
} |t&G&)~:
} 0NCOz(L/
ot@|blVC8
//日志 3@PUg(M
public static void log(String sMsg) +p9LE4g7Q
{ U^[cYTG
System.err.println(sMsg); lruF96C/Y
} VQy9Y
M.xhVgFf)
Hi; K"H]x1
public static void log(int sMsg) OX)#F'Sl}
{ #MhNdH#
System.err.println(sMsg); < v|%K.yd
} u8-a-k5<
} MtpU~c
MiSja#"+A
]5} -y3
/* lL:KaQ0E
**TestMethod.java A~6%,q@^jh
*/ Qb!!J4|!
package NetFox; z'?7]C2b
:LZ-da"QR
( oQ'4,F
public class TestMethod { C2+{U
?(5o@Xq
~/j$TT"
public TestMethod() pau*kMu^}
{ ///xx/weblogic60b2_win.exe tJUVw=
try{ {E3xI2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ne &Xf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ruZYehu1W
SiteFileFetch fileFetch = new SiteFileFetch(bean); uSABh^
fileFetch.start(); pT("2:)x
} V*6l6-y~Ih
catch(Exception e){e.printStackTrace ();} l;XU#6{
$Cz1C
42b.7E
} m0=cMVCA!
rQ`\JE&`
DNm(:%)0
public static void main(String[] args) u iBl#J Q
{ |7svA<<[
new TestMethod(); BCBEX&0hk{
} X|X4L(i
} +dqk6RE
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