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)); T@xaa\bzg
} V'FKgzd
for(int i=0;i<nEndPos.length-1;i++) #Xk/<It
{ 8I~*9MUp
nEndPos = nStartPos[i+1]; {nMCU{*k
} soOfk!b
nEndPos[nEndPos.length-1] = nFileLength; 4axuE]
} t>vr3)W
} G0u H6x?
*|OUd7P:hU
mKJO?7tj
//启动子线程 QL\3|'a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^|%N _ s
for(int i=0;i<nStartPos.length;i++) XMF#l]P
{ W0S\g#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [:/mjO K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ky{@*fg.
nStartPos,nEndPos,i); =d$m@rc0r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +^q-v-
fileSplitterFetch.start(); ^7Ebg5<
} ZEB,Q~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &8dj*!4H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 62o nMY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ju"/#@
nEndPos = " + nFileLength); [U,hb1Wi3
// fileSplitterFetch[nPos.length-1].start(); s(:N>K5*
(g>&ov(d
* $|9e
//等待子线程结束 a|ZJzuqo
//int count = 0; v2ab84 C*
//是否结束while循环 L*6>S_l[
boolean breakWhile = false; lvG+9e3+
8w ]'U
#[]B: n6
while(!bStop) ]4Q~x
{ 6RfS_
write_nPos(); MFz6y":~
Utility.sleep(500); Cy5M0{
breakWhile = true; *iUR1V Y
;y;UgwAM
7WHq'R{@
for(int i=0;i<nStartPos.length;i++) !]MGIh#u
{ L4<=,}KS
if(!fileSplitterFetch.bDownOver) ~PX#' Jr
{ au+a7~0~
breakWhile = false; ,IPryI
break; /BrbP7
} ;It1i`!R
} ahR-^^'$
if(breakWhile) p[%B#(]9,
break; ?:7.3{|Aq
vv D515i
QSvgbjdE
//count++; nc?Oj B
//if(count>4) W . dm1
// siteStop(); >Ft:&N9L{
} BAy)P1
>L^2Z*
-l<[CI
System.err.println("文件下载结束！"); FXbalQ?^
} QaLVIsnfN
catch(Exception e){e.printStackTrace ();} DuRC1@e
} +L pMNnl6
9-.`~v
5r^u7k
//获得文件长度 2SYV2
public long getFileSize() nC\LDeKc
{ N#^o,/
int nFileLength = -1; 1ifPc5j}
try{ ?dvcmXR
URL url = new URL(siteInfoBean.getSSiteURL()); S^)xioKsJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \; zix(N[5
httpConnection.setRequestProperty("User-Agent","NetFox"); `llSHsIkXb
N lB%Qu
b|U3\Fmc
int responseCode=httpConnection.getResponseCode(); b(_PV#@$
if(responseCode>=400) 5xc-MkIRL
{ `IK3e9QpcA
processErrorCode(responseCode); R-5e9vyS
return -2; //-2 represent access is error /&RS+By(i
} XtIY8wsP
^oZD44$
KCfcEz
String sHeader; E>rWm_G
gX]'RBTb
Lu~M=Fh
for(int i=1;;i++) T0BM:ofx
{ W4=<hB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h|.*V$3
//Utility.log(in.readLine()); =mh)b]].4\
sHeader=httpConnection.getHeaderFieldKey(i); 6}q# c
if(sHeader!=null) tSq`_[@
{ I< Rai"
if(sHeader.equals("Content-Length")) bdr!|WZ
{ rY(^6[!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \E,Fe:/g
break; yQ+C}8r5
} lR3JyYY{X
} J,^eq@(
else vU, ]UJ}
break; } mEsb?
} x2z%J,z@4
} >=ng?
catch(IOException e){e.printStackTrace ();} g/x\#W
catch(Exception e){e.printStackTrace ();} G 4C 7
i)+2?<]
+FYhDB~m
Utility.log(nFileLength); QfsTUAfR
e[J0+ x#;r
8}Su7v1
return nFileLength; }P"JP[#E\
} df!n.&\y!
X" ;ly0Mb
Qrt> vOUE7
//保存下载信息（文件指针位置） wvNddu>@
private void write_nPos() ceGo:Aa<)
{ JS!
try{ I)F3sS45}
output = new DataOutputStream(new FileOutputStream(tmpFile)); #zc{N"!
output.writeInt(nStartPos.length); j?P8&Fm<
for(int i=0;i<nStartPos.length;i++) D[R<H((
{ xnG,1doa
// output.writeLong(nPos); 3}X;WE `
output.writeLong(fileSplitterFetch.nStartPos); |%-:qk4rG
output.writeLong(fileSplitterFetch.nEndPos); oj~0zJI
} Y7 `i~K;
output.close(); 9oJ=:E~CP
} [)83X\CO
catch(IOException e){e.printStackTrace ();} e025m}%SU
catch(Exception e){e.printStackTrace ();} Gv zw=~8
} '}T6e1#JV
=H2.1 :'
EcW$'>^
//读取保存的下载信息（文件指针位置） cakb.Q
private void read_nPos() ,-{2ai_
{ $@:z4S(
try{ 7nL3+Pq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b<mxf\b
int nCount = input.readInt(); /=2
nStartPos = new long[nCount]; Qd$!?h
nEndPos = new long[nCount]; j{u!/FD
for(int i=0;i<nStartPos.length;i++) 1?bX$$yl;
{ *$o{+YP
nStartPos = input.readLong(); xYCX}bksh
nEndPos = input.readLong(); NHL{.8L{
} ['rqz1DL5
input.close(); y #Xq@
} |lhVk\X
catch(IOException e){e.printStackTrace ();} GS4 HYF
catch(Exception e){e.printStackTrace ();} ce\ F~8y
} \Q<Ur&J]%
0 SeDBs
G6L /Ny3>_
private void processErrorCode(int nErrorCode) |KxFiH
{ %8lF%uu!x
System.err.println("Error Code : " + nErrorCode); K@zzseQ}=
} pC'GKk 8
=D2x@ank[
< l%3P6|
//停止文件下载 x0!5z1KQh
public void siteStop() ;Y>cegG\
{ RZeU{u<O
bStop = true; #]!0$z|Z
for(int i=0;i<nStartPos.length;i++) uM9[
fileSplitterFetch.splitterStop(); '9MtIcNb
,pz^8NJAI
<H)I06];
} x\Det$3Kx
} r{gJ[%
//负责部分文件的抓取 4(f4 4' ^
**FileSplitterFetch.java |Skk1#
*/ 5B'};AQ
package NetFox; Zom7yI
O8N\
Xbb('MoI63
import java.io.*; 1>SCY_Cv
import java.net.*; ~"+Fp&[9f
9\]%N;;Lo
- zQ
public class FileSplitterFetch extends Thread { t<6`?\Gk
{IW pI *
nsJN)Pt
String sURL; //File URL '_~=C-g
long nStartPos; //File Snippet Start Position Ex ?)FL$4
long nEndPos; //File Snippet End Position `_6!nkq8
int nThreadID; //Thread's ID jtk2>Ol
boolean bDownOver = false; //Downing is over @,63%
boolean bStop = false; //Stop identical b1}P3W
FileAccessI fileAccessI = null; //File Access interface 4#z@B1Jx
,afh]#
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^< ,Np+
{ Jk)^6
this.sURL = sURL; 0vs9# <&V
this.nStartPos = nStart; q=5#t~?
this.nEndPos = nEnd; +FWkhmTv
nThreadID = id; Gv!* Qk4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~$N%UQn?b#
} ~5HI9A4^
}7Si2S
1X4v:rI
public void run() #qk A*WP
{ #`C;@#xr
while(nStartPos < nEndPos && !bStop) | 1Fy
{ PEPBnBA&1
mlR*S<Z
!TRJsL8
try{ a r#p7N
URL url = new URL(sURL); eyZ /%4'q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7mSVL\\^
httpConnection.setRequestProperty("User-Agent","NetFox"); Elt=/,v`!
String sProperty = "bytes="+nStartPos+"-"; JBCcR,\kM*
httpConnection.setRequestProperty("RANGE",sProperty); .VVY]>bJg@
Utility.log(sProperty); RpE69:~PV
Y" s1z<?
Dq!Vo;s2
InputStream input = httpConnection.getInputStream(); -i@1sNx&'
//logResponseHead(httpConnection); 0)V<)"i
`?Yh`P0
ldo7}<s
byte[] b = new byte[1024]; iNR6BP W
int nRead; 5uK:f\y)l
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vMXS%Q
{ %v\0Dm+A
nStartPos += fileAccessI.write(b,0,nRead); ;%Jw9G\h
//if(nThreadID == 1) |\j'Z0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j(!M
} 2B7X~t>8a
xn&G`
<@}~Fp@
Utility.log("Thread " + nThreadID + " is over!"); *]fBd<(8
bDownOver = true; d*=P8QwL|
//nPos = fileAccessI.write (b,0,nRead); /lSz8h2
} -y{o@
catch(Exception e){e.printStackTrace ();} s% "MaDz
} /a%5!)NE%
} &,xN$
h#?L6<*tm
Us'm9 J
//打印回应的头信息 rS>JzbWa
public void logResponseHead(HttpURLConnection con) Z;bzp3v
{ =N`"%T@=
for(int i=1;;i++) c~(+#a
{ N %-Cp)
String header=con.getHeaderFieldKey(i); r>S?,qr
if(header!=null) KvC`6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A('=P}I^
Utility.log(header+" : "+con.getHeaderField(header)); *M5=PQfb
else Y&aFAjj
break; |b{XnD_g
} Au$|@
} Ql>DS~a
bR@ e6.<i
.Y!*6I
public void splitterStop() g]R }w@nJ
{ M-u:8dPu
bStop = true; o+SD(KVn-
} SIjdwr!+ZZ
5C/W_H+9iK
Lc6Wj'G G
} xR2E? 0T
a&~d,vC
T9\wkb.
/* \X5{>nNh
**FileAccess.java bort2k
*//文件访问(定位，写) jQzq(oDQw
package NetFox; rl9YB %P
import java.io.*; DPJ#Y -0
M"2Tuwz
5bX SN$7|
public class FileAccessI implements Serializable{ }s=D,_}m
bE.,)GY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NyI0[]z
RandomAccessFile oSavedFile; j`A%(()d
long nPos; }3F8[Td.~N
FyX\S=
m(E-?VMHo
public FileAccessI() throws IOException f( 5c
{ 1HG~}E
this("",0); v!T%xUb0
} D(D:/L8T,
CN@bJo2
wQ qI@
public FileAccessI(String sName,long nPos) throws IOException Y 9]
{ ~U#afGH$
oSavedFile = new RandomAccessFile(sName,"rw"); ~h6aw
this.nPos = nPos; ,F(nkbt
oSavedFile.seek(nPos); mL`,v WL/`
} |GtTz&
@FKNB.>
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public synchronized int write(byte[] b,int nStart,int nLen) .{x-A{l
{ 9l9nT
int n = -1; uPc}a3'?
try{ -! Hn,93
oSavedFile.write(b,nStart,nLen); L6Ykv/V
n = nLen; NS@j`6/U
} -;cZW.<
catch(IOException e) C1^=se
{ 7A?~a_Ep
e.printStackTrace (); Enn7p9&
} IlJ6&9
.}S9C]d:a
okJ+Yl.[?7
return n; 5*u0VabC<
} +uKh]RP
vO!p8r F
PXG)?`^NX
} S\K;h/;V
^%V'l-}/
lN#W
/* v{ Md4p
**SiteInfoBean.java Tz3 L#0:j
*/ 9 o6ig>C
package NetFox; 9F)+p7VJq
n#XiCo_\
"hi?/B#d
public class SiteInfoBean { DZ -5A
HtB>#`'
0]=|3-n
private String sSiteURL; //Site's URL -iWt~
private String sFilePath; //Saved File's Path z^+f3-Z
private String sFileName; //Saved File's Name j'FSd*5m
private int nSplitter; //Count of Splited Downloading File ;rYL\`6L
1=gE,k5H
<7R\#
public SiteInfoBean() A ><
{//nSplitter的缺省值为5 3maiBAOKz
//default value of nSplitter is 5 UXwnE@`F
this("","","",5); mH2XwA|
} Tt#4dm-
0>Iy`>]
G vMhgG=D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F7lhLly
{ SYd4 3PA
sSiteURL= sURL; ;rZR9fR
sFilePath = sPath; lJ;7sgQ#
sFileName = sName; P*Va<'{:{
this.nSplitter = nSpiltter; LgXc}3
TeaP\a
Q.X)QCp#r
} z ^t6VFM
T#kPn#|
0w9)#e+JS
public String getSSiteURL() TELN4*
{ <5(P4cm9
return sSiteURL; _0dm?=
} &SuWmtq
_Y@vO
W5 ^eCYHoi
public void setSSiteURL(String value) r:0F("},
{ z5`AJrj%
sSiteURL = value; *Z'*^Y1le
} V .+ mK|)
Vc0C@*fVM
lWr=79
public String getSFilePath() ln.'}P
{ {7swE(N
return sFilePath; XE8>&&X
} T1AD(r\W5
hB/4.K]8
a!rU+hiC
public void setSFilePath(String value) __N< B5E
{ VbX+`CwH
sFilePath = value; Ahl-EVIr<
} 4.Luy
B8A-|S!,U
hZ@frbuowk
public String getSFileName() Z./$}tVUG
{ Kv(2x3("
return sFileName; E;m]RtvH
} VRden>vKN
CqK&J /8
Kz>bfq7
public void setSFileName(String value) iY@wg 8ry
{ S&(MR%".
sFileName = value; $>^DkrOd
} ZYRZ$87jZ
e=uElp'%
C:z+8wt
public int getNSplitter() LB9D6,*t
{ khFr%u ?S
return nSplitter; zv[$N,
} y2Eq-Ie
96G8B62
n}0n!Pr^
public void setNSplitter(int nCount) \tR](, /
{ V+`gkWe/
nSplitter = nCount; y,&'nk}
} 0xE37Ld,
} 2IMU &
3s%Kw,z
h&5bMW
/* GZ=7)eJ~<
**Utility.java mQL8ec_c
*/ WXq=FZ-
package NetFox; FTu6%~M/
%vF,wQC
l-^2>K[
public class Utility { s"OP[YEke/
9mA6nmp
HrOq>CSR
public Utility() i28WgDG)5
{ A]<+Aq@{
)ZZjuFQJ)
wPr9N}rf
} Ygeg[S!7
8M6 Xd]{%
//线程睡眠 M~/Pk7CC
public static void sleep(int nSecond) b"4'*<=au
{ '%Fg+cZN\
try{ -9PJ4"H
Thread.sleep(nSecond); K Eda6zZH
} I:|<};mm
catch(Exception e) Fw{:fFZC[
{ %<dvdIB
e.printStackTrace (); WZ@hP'Zc
} I1f4u6\*X
} }xx"
,5*Z<[*
//日志 )wZ;}O
public static void log(String sMsg) L<D<3g|4
{ 8NF93tqD6
System.err.println(sMsg); 7C;oMh5
} @ra^0
1>yh`Bp\=
zG\& ZU
public static void log(int sMsg) bwR$910b
{ kh4., \'
System.err.println(sMsg); 8n&Gn%DvX
} !l6Ez_'
} P^3`znq{
$Wy(Wtrx|
%3%bRP
/* o:wI{?%-3
**TestMethod.java [,bra8f[C
*/ ;OMR5KAz
package NetFox; N4HIQ\p
6y+_x'
hr@kU x
public class TestMethod { $.+_f,tU
kuq&8f~!
2`'g 9R
public TestMethod() ~:JoKm`vU
{ ///xx/weblogic60b2_win.exe aRV.;S
try{ WWEZTFL:j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #"qP4S2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Cg8s9qE?
SiteFileFetch fileFetch = new SiteFileFetch(bean); +,Ud 3iS
fileFetch.start(); PtTL tiE~
} ikd1KF+I
catch(Exception e){e.printStackTrace ();} WqO4_;X6/
jd.{J{o
PQd*)6K:A
} u~xfI[8C
p3,m),
JW},7Ox
public static void main(String[] args) ?S<`*O +
{ MvKr~
new TestMethod(); =vs]Kmm
} /2f
} %f?Z/Wn
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