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)); k Rp$[^ma
} }$'T=ay&
for(int i=0;i<nEndPos.length-1;i++) h\OMWJ~
{ .u9,w
nEndPos = nStartPos[i+1]; 0qo:M3
} !JwR[X\f
nEndPos[nEndPos.length-1] = nFileLength; ~jOk?^6
} HS 1zA
} +@yTcz
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e:WKb9nT
//启动子线程 @avG*Mr^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n]WVT@
for(int i=0;i<nStartPos.length;i++) vF$sVu|B
{ E$E#c8I:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~fF;GtP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iXuSFman
nStartPos,nEndPos,i); H}}C>p"!,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'WJ3q|o/
fileSplitterFetch.start(); IdWFG?b3
} 0\yA6`}!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +Rd;>s*.Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -f8iq[F5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a.s5>:Ct
nEndPos = " + nFileLength); g,5Tr_
// fileSplitterFetch[nPos.length-1].start(); ;Z{jol
sb*)K,U
ABnJ{$=n#
//等待子线程结束 %pImCpMR
//int count = 0; 6n$g73u<=3
//是否结束while循环 Z {*<Gx
boolean breakWhile = false; @L5s.]vg=
V82N8-l
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while(!bStop) xU;;@9X
{ IpI|G!Y,
write_nPos(); 7,EdJ[CR$
Utility.sleep(500); Ya-kMUW
breakWhile = true; I=9sTR)
w|8T6W|w
jB%aHUF;
for(int i=0;i<nStartPos.length;i++) -1tiy.^$F
{ xr1,D5
if(!fileSplitterFetch.bDownOver) TKZ[H$Z
{ W(,3j{d2i
breakWhile = false; 'P3jUc)
break; EHX/XM
} F>s5<pKAX
} #hF(`oX}4K
if(breakWhile) oD&axNk
break; <]h?_)
&O.lIj#FR
k^*S3#"
//count++; 3/0E9'
//if(count>4) (od9adSehV
// siteStop(); *t,1(Gw|7q
} )V?:qCuY>
N)^` 15w
{E$smX
System.err.println("文件下载结束！"); 6k*,Yei
} R*r;`x
catch(Exception e){e.printStackTrace ();} @pO2A6Ks
} 4|Ay;}X \
#8qhl
.FpeVjR''
//获得文件长度 ?I332,,q
public long getFileSize() "TP^:Ln
{ GEUC<bL+
int nFileLength = -1; S<UWv@`U"
try{ 0;2"X[e
URL url = new URL(siteInfoBean.getSSiteURL()); @PAT|6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2*ByVK
httpConnection.setRequestProperty("User-Agent","NetFox"); HGlQZwf
~l"]J'jF"H
h0)Dj(C
int responseCode=httpConnection.getResponseCode(); k}FmdaPI'
if(responseCode>=400) I::|d,bR!
{ |!E: [UH
processErrorCode(responseCode); JBt2R=
return -2; //-2 represent access is error $bsD'Io
} S>V+IKW;(
QSSA)
T?HW=v_a
String sHeader; }YCpd)@
0<#>LWaM_
=C 7WQ
for(int i=1;;i++) LeaJ).Maw
{ FDCc?>,o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4Be'w`Q {
//Utility.log(in.readLine()); `R6dnbH
sHeader=httpConnection.getHeaderFieldKey(i); _UGR+0'Q\
if(sHeader!=null) z~(3S8$
{ H?_>wQj&
if(sHeader.equals("Content-Length")) sFV&e->AN\
{ 6&`hf >
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h1 pEC
break; 5L\&"['
} dpSNh1
} =bJ7!&
else zy(NJ
break; x7ZaI{
} B"?ivxM:U
} #.j}:
catch(IOException e){e.printStackTrace ();} T:I34E[
catch(Exception e){e.printStackTrace ();} 7]H<ou
.W s\%S
w;;9YFBdM
Utility.log(nFileLength); ,=V9?
<NXJ&xs-+
XR|U6bf]
return nFileLength; Gy)2
} D$Eq~VQ
yc+pNC)ue_
! G3Gr
//保存下载信息（文件指针位置） AW8*bq1
private void write_nPos() B;e (5y-
{ 03H0(ku=
try{ y4)iL?!J~
output = new DataOutputStream(new FileOutputStream(tmpFile)); M>[e1y>7
output.writeInt(nStartPos.length); z"P/Geb:O
for(int i=0;i<nStartPos.length;i++) `3yK<-
{ Z@,[a
// output.writeLong(nPos); oju,2kpH7#
output.writeLong(fileSplitterFetch.nStartPos); %y_{?|+
output.writeLong(fileSplitterFetch.nEndPos); TyhO+;
} GRh430V[
output.close(); |p.|zH
} H)+QkQb}
catch(IOException e){e.printStackTrace ();} w)C5XX30;
catch(Exception e){e.printStackTrace ();} S#:l17e3
} uH]oHh!}j
v=d16
CorV!H4
//读取保存的下载信息（文件指针位置） F:N8{puq5
private void read_nPos() vb6kr?-i*
{ i&YWutG
try{ stQ_Ke
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C),i#v
int nCount = input.readInt(); :g~_
nStartPos = new long[nCount]; R*/s#*gmL
nEndPos = new long[nCount]; F3[,6%4v
for(int i=0;i<nStartPos.length;i++) Q[{RNab
{ 5]xSK'6W
nStartPos = input.readLong(); niqknqW<t
nEndPos = input.readLong(); $*;`$5.x^
} p(6 sN=
input.close(); P; h8
} ?N^1v&Q
catch(IOException e){e.printStackTrace ();} ?4^ 0xGyE
catch(Exception e){e.printStackTrace ();} +z4E:v
} &`oybm-p(
TV=K3F5)M
1mD)G55Ep
private void processErrorCode(int nErrorCode) dci<Rz`h
{ 5th?m>
System.err.println("Error Code : " + nErrorCode); ,x$^^
} 7=%Oev&0g-
kH8/8
dIfy!B"
//停止文件下载 Y_K W9T_
public void siteStop() NSM7n= *nh
{ Ol~M BQs
bStop = true; l dqU#{
for(int i=0;i<nStartPos.length;i++) pH3<QNq5
fileSplitterFetch.splitterStop(); PMUW<UI
Z&O6<=bg!
tzthc*-<
} jD${ZIv
} SA7(EJ95
//负责部分文件的抓取 `/^ _W <
**FileSplitterFetch.java M*f]d`B
*/ P?S]Q19Q4
package NetFox; s VHk;:e>x
sn"z'=ch
xv&h>GOg
import java.io.*; hD=.rDvO
import java.net.*; |c^?tR<
<v'&Pk<
)U=]HpuzI
public class FileSplitterFetch extends Thread { C!|LGzs0
z;!"i~fFK
rtfRA<
String sURL; //File URL 2,wwI<=E'
long nStartPos; //File Snippet Start Position N<1+aL\
long nEndPos; //File Snippet End Position BM'!odRv
int nThreadID; //Thread's ID 2?SbkU/3|P
boolean bDownOver = false; //Downing is over 'NZ=DSGIy
boolean bStop = false; //Stop identical kRc+OsY9
FileAccessI fileAccessI = null; //File Access interface xx(C$wCJ
R<U]"4CBx
$dF3@(p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G:p85k`
{ 5dB62dqN
this.sURL = sURL; P#7=h:.522
this.nStartPos = nStart; *mVg_Kl
this.nEndPos = nEnd; lPI~5N8
nThreadID = id; s M*ay,v;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #=={h?UDT
} 9v[V"m`M
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a eeor
public void run() .p,VZ9
{ 6y~F'/ww
while(nStartPos < nEndPos && !bStop) Rq%Kw> {&
{ Q2D!Agq=D
N-]/MB8
W"^=RY
try{ 5|nc^ 12
URL url = new URL(sURL); <l$ d>,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X.#)CB0c1Q
httpConnection.setRequestProperty("User-Agent","NetFox"); P6R_W
String sProperty = "bytes="+nStartPos+"-"; t:5-Ro
httpConnection.setRequestProperty("RANGE",sProperty); #,u|*O:
Utility.log(sProperty); z V\+za,
t2s/zxt
wV"`Du7E;
InputStream input = httpConnection.getInputStream(); "J`&"_CyZ
//logResponseHead(httpConnection); +l/v`=C
CF2Bd:mfZ
:Ys~Lt54
byte[] b = new byte[1024]; S.)Jp-&K
int nRead; l6&\~Z(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) avL_>7q
{ r]UF<*$
nStartPos += fileAccessI.write(b,0,nRead); V@!)Pw
//if(nThreadID == 1) \1Xk[%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BUJ\[/
} qfyZda0d
|7tD&9<
=I'3C']Z W
Utility.log("Thread " + nThreadID + " is over!"); #F.jf2h@
bDownOver = true; ;,C]WZ.w
//nPos = fileAccessI.write (b,0,nRead); R2gV(L(!!
} PmRvjSIG
catch(Exception e){e.printStackTrace ();} M[gL7-%w\
} yGf7k>K'
} ]mb8R:a1
U8w_C\Q
E5d$n*A
//打印回应的头信息 Z0jgUq`r
public void logResponseHead(HttpURLConnection con) /}(d'@8p
{ :Ko6.|
for(int i=1;;i++) ~vFa\7sf
{ ( %\7dxiK
String header=con.getHeaderFieldKey(i); $+!dP{
if(header!=null) ba);f[>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2t-w0~O
Utility.log(header+" : "+con.getHeaderField(header)); ^,acU\}VqP
else NEIkG>\7q
break; >F7w]XH
} B6Vlc{c5SO
} e~9O#rQI
BVNW1<_:
V@G#U[D
public void splitterStop() N8b\OTk2
{ fI613ww]
bStop = true; KLg1(W(
} 3}0\W.jH
6'r8.~O
DPTk5o[
} .$%p0Yx+
t'vt'[~,U
0jf6 z-4
/* \ ;npdFy
**FileAccess.java ,vJt!}}
*//文件访问(定位，写) HYmC3
package NetFox; l%0bF9\
import java.io.*; " B#|C'
QO/0VB42
6lSz/V;
public class FileAccessI implements Serializable{ uZS:
NQk aW)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 GiV%Hcx
RandomAccessFile oSavedFile; zTF{ g+
long nPos; O?JJE8~']
NXU:b"G S
V&M*,#(?
public FileAccessI() throws IOException 3'0Pl8
{ _rT\?//B
this("",0); CubQ6@,
} ]:<!(
G<;~nAo?f0
;sZG=y@
public FileAccessI(String sName,long nPos) throws IOException s[yWBew
{ Cbw *?9d
oSavedFile = new RandomAccessFile(sName,"rw"); &AQqI
this.nPos = nPos; fu/8r%:h
oSavedFile.seek(nPos); hmO2s/~
} _M&TT]a
= xO03|T;6
n/+X3JJ
public synchronized int write(byte[] b,int nStart,int nLen) /BL:"t@-
{ nT6y6F_e
int n = -1; ,,'jyqD
try{ H}^'
oSavedFile.write(b,nStart,nLen); +I3jI <
n = nLen; UN]gn>~j
} SS=<\q#MS
catch(IOException e) >cu%Cs=m
{ KP&+fDa
e.printStackTrace (); { mi}3/
} SB_Tzp
{PHH1dC{
"|SMRc
return n; 2/LSB8n|
} k~Ex_2;#
'cW^S7
H U|.5tP
} -@W9+Zf5
,fkvvM{mq
> ;,S||
/* -/yqiC-yx
**SiteInfoBean.java Da=EAG-{7
*/ > H!sD\b
package NetFox; )ZG;.j
3o<d=@`r
)dXa:h0RZ
public class SiteInfoBean { _bFUr
M";qo6
p4' .1.@
private String sSiteURL; //Site's URL +)Z]<O
private String sFilePath; //Saved File's Path IC`3%^
private String sFileName; //Saved File's Name ')X(P>
private int nSplitter; //Count of Splited Downloading File DXFu9RE\{
51#*8u+L
$ V^gFes
public SiteInfoBean() p@m0Oi,=
{//nSplitter的缺省值为5 z:Ml;y
//default value of nSplitter is 5 bz4Gzp'6k
this("","","",5); Hq3|>OqC2Q
} K$CC ~,D
_5oTNL2
F^i3e31*t
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Wv;0PhF
{ sZ.<:mu[
sSiteURL= sURL; (m~>W"x/
sFilePath = sPath; = tv70d'
sFileName = sName; 4"d,=P.{
this.nSplitter = nSpiltter; 7=G2sOC
M&Uy42,MR
/x<g$!`X
} mxa~JAlN_
]-=L7a
|.<_$[v[x
public String getSSiteURL() p~pD`'%
{ ]g_VPx"
return sSiteURL; mzgt>Qtkz=
} *Rgr4-eS
H|9t5
aO6\e>
public void setSSiteURL(String value) &qv~)ZM$
{ Y0LZbT3
sSiteURL = value; IkrB}
} Y-VDi.]W
]z'&oz
=~D? K9o
public String getSFilePath() iSW2I~PD
{ L4By5)
return sFilePath; o3J#hQrl
} H;Wrcf2
O[@!1SKT0
xQoZ[
public void setSFilePath(String value) mw@Pl\=
{ +C(-f
sFilePath = value; H4$qM_N
} 'o AmA=
]33!obM
TOwd+]B
public String getSFileName() &?<uR)tl
{ X Xque-
return sFileName; dkQ4D2W*\
} (jc@8@Wo.
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y Zafq"o
public void setSFileName(String value) &Mh.PzO=b
{ SSK}'LQ
sFileName = value; ?=u?u k<-
} )M0YX?5AR
r`H}f#.KR
#M,&g{
public int getNSplitter() gf|uZ9{
{ u'YXI="(
return nSplitter; |z-f8$
} Y:^hd809
Hon2;-:]{]
-Q WvB
public void setNSplitter(int nCount) !09)WtsEfx
{ E^F"$Z"N
nSplitter = nCount; DfXkLOGik
} tOwn M1 :(
} !_QI<=X
f|[7LIdh-
(gt\R}
/* g4K+AK
**Utility.java 'aSsyD!?<
*/ [xS7ae
package NetFox; s~M4.06P
+^.Yt0}
umYsO.8
public class Utility { ]so/AdT9hA
TxrW69FV7
|9*Rnm_
public Utility() rQ*+ <`R}
{ c%&,(NJ]K
m#"_x{oa
v%tjZ5x
} <Q[%:LD
3Y#Q'r?
//线程睡眠 `3TR`,=
public static void sleep(int nSecond) &l(T},-X
{ 7)?C+=,0
try{ H2X_WSwm
Thread.sleep(nSecond); @0+\:F
} P1#g{f
catch(Exception e) 5Xq+lLW>
{ 2/-m-5A
e.printStackTrace (); ($di]lbsT
} corm'AJ/
} |J$A%27
xUJ(tG3
//日志 (zhZ}C,VF
public static void log(String sMsg) vNO&0~
{ B'Yx/c&n
System.err.println(sMsg); 0s n$QmW:
} NdK`-RT
(,At5T
w,%"+tY_
public static void log(int sMsg) *5'8jC"2g
{ YPK@BmAdE
System.err.println(sMsg); rZKh}E
} -l[H]BAMXy
} K,4Ig!
z#{Y>.b
FZ*"^=)`G
/* I4Do$&9<D
**TestMethod.java l\_!oa~
*/ ?1Nz ,Lc$
package NetFox; B`SX3,3
<spG]Xa<
x[A|@\Z
public class TestMethod { 757&bH|a
l)r\SE1
y-pdAkDh
public TestMethod() :zW? O#aL-
{ ///xx/weblogic60b2_win.exe Z$z-Hx@%
try{ {_7hX`p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @&jR^`Y.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \kE0h\
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1P)K@j
fileFetch.start(); pH~\~
} %1&X+s3
catch(Exception e){e.printStackTrace ();} G^'We6<
g;l K34{
kNuvJ/St
} ^-%'ItVO
8vx ca]DcV
"6,fIsU
public static void main(String[] args) Tzd#!Lvm:,
{ ~-"CU:$o
new TestMethod(); h;=~%2Y
} F:zmO5L5
} ?e%*q^~Cu
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