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)); h*i9m o
} C})'\1O%
for(int i=0;i<nEndPos.length-1;i++) Zyf P;&
{ wq!iV |
nEndPos = nStartPos[i+1]; q(M:QWA q
} <%?#AVU[
nEndPos[nEndPos.length-1] = nFileLength; o4y']JSN
} ~FU@wV^
} eD?3"!c!
j]rz]k
uBrMk
//启动子线程 DGESba\2+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;q>9W,jy
for(int i=0;i<nStartPos.length;i++) zCaT tb|@
{ XzIx:J6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w?Ju5 5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R9+jW'[K
nStartPos,nEndPos,i); V9NTs8LKc
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k?GD/$1t
fileSplitterFetch.start(); iA }vKQ
} 5s{j=.O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;]2s,za)qs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SkQswH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EbNd=Z'J
nEndPos = " + nFileLength); Dh4 6o|P
// fileSplitterFetch[nPos.length-1].start(); 8 .>/6M
l`9t}
0#o/^Ah
//等待子线程结束 k(VB+k"3
//int count = 0; ,5 j"ruZ
//是否结束while循环 q!~ -(&S
boolean breakWhile = false; a?h*eAAc.
Hh;:`;}
gY-5_Ab
while(!bStop) 7r#ymQ
{ k44Q):ncY7
write_nPos(); 5*%#o
Utility.sleep(500); "UFs~S|e
breakWhile = true; ]y{WD=T
OPJ: XbG
Y$K!7Kq
for(int i=0;i<nStartPos.length;i++) Cizvw'XDV
{ igL<g
if(!fileSplitterFetch.bDownOver) E>LkJSy=
{ 5Z/7kU=I
breakWhile = false; T4/fdORS
break; w'4AJ Q|;
} :nN1e
} W*DVi_\$y
if(breakWhile) =<@2#E)
break; !|waK~jK
?4H#G)F
Z6C=T;w
//count++; @oP_;G
//if(count>4) #65^w=Sp}
// siteStop(); ? 8aaD>OR$
} /wShUR{
eYUr-rN+)z
WUc#)EEM)
System.err.println("文件下载结束！"); {~GYj%-^
} Rgy-OA
catch(Exception e){e.printStackTrace ();} f>o,N{|
} inb^$v
9I7\D8r
}GMbBZ:nKK
//获得文件长度 ^jB8Q
public long getFileSize() RrZM&lXY
{ }kHdK vZ
int nFileLength = -1; ZIR0PQh\
try{ P;[OWSR[d
URL url = new URL(siteInfoBean.getSSiteURL()); 1F'1>Bu~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WO5O?jo'
httpConnection.setRequestProperty("User-Agent","NetFox"); b3-eR5U/
}TQ{`a@
Am0{8 '
int responseCode=httpConnection.getResponseCode(); Qhi '')Q
if(responseCode>=400) Y/<lWbj*A
{ '+>fFM,*B
processErrorCode(responseCode); / O/`<
return -2; //-2 represent access is error 7M_U2cd|TD
} gbeghLP[?
/I5X"x
:AdDLpk3j
String sHeader; -~[9U,
/^{BUo
7\zZpPDV
for(int i=1;;i++) c\6+=\
{ 9fnA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YYEJph@06q
//Utility.log(in.readLine()); %=AxJp!a
sHeader=httpConnection.getHeaderFieldKey(i); zJDSbsc$%
if(sHeader!=null) =o}"jVE
{ &;,,H< p
if(sHeader.equals("Content-Length")) z{"2S="
{ lU^;Z6f
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {CG_P,FO
break; 3nZ9m
} jCAC `
} AsS$C&^
else r)9Dy,
break; unJid8Lo
} 87%*+n:?*
} EpS(o>'
catch(IOException e){e.printStackTrace ();} jc[_I&Oc_
catch(Exception e){e.printStackTrace ();} 8[CB>-9
|{*}|
,mS/h~-5n
Utility.log(nFileLength); t>GfM
q+KzIde|%
"LYh7:0s!k
return nFileLength; R3)57OyV
} Q-Ux<#
\l"&A
%<?0apO
//保存下载信息（文件指针位置） E5el?=,i
private void write_nPos() _zt19%Wg
{ - K%,^6
try{ k%wn0Erd
output = new DataOutputStream(new FileOutputStream(tmpFile)); Xtz-\v#0o'
output.writeInt(nStartPos.length); KTvzOI8
for(int i=0;i<nStartPos.length;i++) pL1Q7&&c0
{ 6iEhsL&K
// output.writeLong(nPos); zf4Ec-)
output.writeLong(fileSplitterFetch.nStartPos); fPi3sb`}
output.writeLong(fileSplitterFetch.nEndPos); \T]EZ'+O
} f\+fo
output.close(); Qu5UVjbE,
} L%v^s4@
catch(IOException e){e.printStackTrace ();} ,uw132<b
catch(Exception e){e.printStackTrace ();} ONNpiK-
} ,:~0F^z
6)oLus
4Wy<?O2
//读取保存的下载信息（文件指针位置） A7!g
private void read_nPos() 72sD0)?A
{ E3@QI?n^^
try{ jztq.2-c#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l$K,#P<)
int nCount = input.readInt(); AM"Nn L"
nStartPos = new long[nCount]; 4!asT;`'
nEndPos = new long[nCount]; Q6o(']0
for(int i=0;i<nStartPos.length;i++) R1F5-#?'E
{ {7!UQrm<
nStartPos = input.readLong(); )eUW5 tS
nEndPos = input.readLong(); Zh5RwQNE~
} p~ C.IG
input.close(); VL[R(a6c <
} -/_L*oYli
catch(IOException e){e.printStackTrace ();} AC O)Dt(Y
catch(Exception e){e.printStackTrace ();} GV)<Q^9
} A^ _a3$,0
OA:%lC!
jENr>$$
private void processErrorCode(int nErrorCode) O8|5KpXd@
{ KZ!3j_pKy
System.err.println("Error Code : " + nErrorCode); nd;fy$<J\
} d!KsNkk
1Z[/KJ
|K?#$~
//停止文件下载 ;})5:\h
public void siteStop() 7'wS\/e4a
{ Qr1e@ =B
bStop = true; ZpUCfS)|&
for(int i=0;i<nStartPos.length;i++) j8|g!>Nv
fileSplitterFetch.splitterStop(); w ;daC(:
hYQ_45Z*?
*A}cL
} g}laG8
} st"{M\.p
//负责部分文件的抓取 Oz|K8p
**FileSplitterFetch.java b}T6v
*/ zkTp`>9R
package NetFox; |IunpZV
Ngb(F84H?
v+jsC`m
import java.io.*; KXV[OF&J
import java.net.*; AtR?J"3E
*lef=:&,,
5XuT={o
public class FileSplitterFetch extends Thread { ^QuiH'
?ER-25S
{]z4k[;.h
String sURL; //File URL ,!V]jP)
long nStartPos; //File Snippet Start Position @&D?e:|!U
long nEndPos; //File Snippet End Position ;> m"x
int nThreadID; //Thread's ID X1ZgSs+i
boolean bDownOver = false; //Downing is over s>0Nr
boolean bStop = false; //Stop identical [D5t{[i
FileAccessI fileAccessI = null; //File Access interface 7_2kDDW0
<foCb%$(?
%>gW9}kB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #W.vX?-'0
{ y=Mq(c:'UN
this.sURL = sURL; b':|uu*/
this.nStartPos = nStart; }F+zs*S
this.nEndPos = nEnd; Qu,8t8
nThreadID = id; d:G]1k;z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I@Xn3oN
} O]f/r,4@
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JQ:Ri
public void run() E;21?`x5
{ #,{+3Y&5-+
while(nStartPos < nEndPos && !bStop) ^m_yf|D$
{ nm7;ieMfr
H:p Z-v*
fYE(n8W3
try{ /6O??6g
URL url = new URL(sURL); 1FtM>&%4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uxg9yp@|
httpConnection.setRequestProperty("User-Agent","NetFox"); X0-IRJ[
String sProperty = "bytes="+nStartPos+"-"; dD<fn9t
httpConnection.setRequestProperty("RANGE",sProperty); TO2c"7td
Utility.log(sProperty); v^ d]rSm
Jc)^49Rf
U/lM\3v/e
InputStream input = httpConnection.getInputStream(); nA?Hxos
//logResponseHead(httpConnection); zrVC8Wb
6h3HDFS7s
u*
byte[] b = new byte[1024]; azjEq$<M
int nRead; y2O4I'/5<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (Qgde6
{ 2xw6 5z
nStartPos += fileAccessI.write(b,0,nRead); <8UYhGK
//if(nThreadID == 1) iYnEwAoN;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;,&8QcSVY
} &[2U$`P`V
+.y .Mp
\D>$aLO*?
Utility.log("Thread " + nThreadID + " is over!"); MxzLK%am
bDownOver = true; Knhp*V?
//nPos = fileAccessI.write (b,0,nRead); q9"=mO0J+
} ,]}?.g
catch(Exception e){e.printStackTrace ();} V|)>{Xdn
} VL9-NfeqR
} Y^%T}yTtq
bVmAtm[
~.%K/=wK@
//打印回应的头信息 `V[!@b:
public void logResponseHead(HttpURLConnection con) iut`7
{ 5>J=YLq
for(int i=1;;i++) U|G|l|Bl
{ c:83LZ
String header=con.getHeaderFieldKey(i); vd`}/~o
if(header!=null) @H!$[m3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g<*BLF
Utility.log(header+" : "+con.getHeaderField(header)); )XQ`M?**M
else ?muzU.h"z
break; B= keBO](@
} %LXM+<N8
} e6=]m#O9
]*O/+
]CU]pK?nq
public void splitterStop() >r &;3:"
{ 9;yn}\N `
bStop = true; 74<!&t
} PNW \*;j
7^}Ll@
0iCPi)B
} 1B*WfP~
Qr#1u
k7tYa;C
/* .^)UO
**FileAccess.java 2!N8rHRt
*//文件访问(定位，写) J==SZ v
package NetFox; UR(-q
import java.io.*; W~_t~Vg5
}0,>2TTDN
?}Z1(it0
public class FileAccessI implements Serializable{ UEak^Mm;=2
4Ij-Ilg)%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i?Ss:v^
RandomAccessFile oSavedFile; X\p,%hk \
long nPos; \b}~2oX
MH|]\
#6Xs.*b5C
public FileAccessI() throws IOException P7B:%HiAx
{ Qy#)Gxp
this("",0); K}[>T(0E
} \qsw"B*tv`
dBO@6*N4c
VC5_v62&.
public FileAccessI(String sName,long nPos) throws IOException %tA57Pn>
{ F>]#}_
oSavedFile = new RandomAccessFile(sName,"rw"); eUS
this.nPos = nPos; 'H9=J*9oG
oSavedFile.seek(nPos); Bs`$i ;&
} c41: !u^
PR<||"03
fIoIW&iy
public synchronized int write(byte[] b,int nStart,int nLen) h5 Vv:C
{ +b;hBb]R
int n = -1; W{XkVKe1a
try{ +@X5!S6
oSavedFile.write(b,nStart,nLen); 5)1+~B
n = nLen; ^EVc95|Z
} {Hr$wa~
catch(IOException e) wLuv6\E
{ {|9}+ @5Q1
e.printStackTrace (); 4t4olkK3Oa
} "S~_[/q
(_* wt]"'
A`O<6
return n; +.[\g|G
} _9:@Vl]Q@
xChI,~i
lA>\Ko
} j:5%ppIY
,1Qd\8N9
31Cq22"
/* i5hD#
**SiteInfoBean.java G@S&1=nj3
*/ ~;-9X|
package NetFox; 9?+9UlJ7K
mzL[/B#>M
]O:M$ $
public class SiteInfoBean { ps1YQ3Ep&
;D ~L|
lfk9+)
private String sSiteURL; //Site's URL n)8Yj/5
private String sFilePath; //Saved File's Path %R_{1GrL'c
private String sFileName; //Saved File's Name m$>iS@R
private int nSplitter; //Count of Splited Downloading File =fc:6JR
^ L:cjY/
zH)_vW
public SiteInfoBean() 9-*NW0
{//nSplitter的缺省值为5 ]kktoP|D
//default value of nSplitter is 5 B%<e FFV\
this("","","",5); kL@Wb/K JP
} dOa!htx]
S_J :&9L
"YFls#4H-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h?@G$%2
{ )tZ`K |
sSiteURL= sURL; .M|>u_<Qd
sFilePath = sPath; f<[jwhCWV
sFileName = sName; i~=s^8n`l
this.nSplitter = nSpiltter; l52a\/
jStmS2n
kD~uGA
} Y{Ap80'\6
QHf$f@bjI
g+q@i{Yn
public String getSSiteURL() E|Bd>G
{ $]d*0^J 6
return sSiteURL; ^Uw[x\%#gD
} p|6v~
~JZ3a0$^
O]u",J5
public void setSSiteURL(String value) #,f{Ok+
{ NlR"$
sSiteURL = value; V:K;] h*!
} <SXZx9A!
#*IVlchA"B
f%fa{
public String getSFilePath() [p;*r)f2}
{ %j]STD.E
return sFilePath; ,j980/
} RpQ*!a~O
='Oj4T
H;vZm[\0N-
public void setSFilePath(String value) QrjDF>
{ i3V/`)iz
sFilePath = value; Hw_o w?
} [$:,-Q@
"h$R ]~eG
'%4P;HO
public String getSFileName() vgPUIxB@
{ D(Ix!G/
return sFileName; !c8L[/L
} /J%do]PDl
2YQ#-M
i*tv,f.(
public void setSFileName(String value) ~@c-*
{ g,lY ut
sFileName = value; 0%Q9}l#7
} 8Pmwzpk02
9 pKm*n&
X BI;Lg
public int getNSplitter() @6.]!U4w
{ eqzTQen8q
return nSplitter; lJ/6-dP
} ~Yk"Hos
+mWjBY
*re 44
public void setNSplitter(int nCount) 7c1+t_Ew
{ 8GB]95JWwp
nSplitter = nCount; ;<6"JP>0
} b :\D\X
} P.4E{.)(
g^lFML| %
.j 'wQ+_
/* w!,QxrOV~
**Utility.java D$pj#
*/ 3z,2utH
package NetFox; mCk5B*Jy
E2:D(7(;l
qzdaN5
public class Utility { c cr" ep
;~ee[W$1
/Dd\PjIH{
public Utility() pcpxe&S
{ kyAs'R@z
FLbZ9pX}
Baq ~}B<
} [}k|
&l^n4
//线程睡眠 BR3mAF
public static void sleep(int nSecond) /RF%1!M K
{ 1M+Zkak7p
try{ NhlJ3/J j
Thread.sleep(nSecond); 5ZsDgOeY
} Sr7@buF
catch(Exception e) m!!;/e?yx
{ gE=Wcb!
e.printStackTrace (); /#\?1)jCK
} Y@:3 B:m#
} m.146
m^0A?jBrR
//日志 Qv!rUiXq
public static void log(String sMsg) pGk"3.ce
{ eiB(VOJ
System.err.println(sMsg); Q<'@V@H
} \]a uSO
PJwEA
.HDebi
public static void log(int sMsg) "o==4?*L
{ =tq7z =k
System.err.println(sMsg); E3tj/4:L
} '}zT1F* p=
} *^6k[3VY
nOuN|q=C
t'Htx1#Zc[
/* cUM_ncYOP
**TestMethod.java ] zIfC>@R
*/ yy))Z0E5
package NetFox; =#'+"+lQ }
GU#Q}L2
>0M:&NMda
public class TestMethod { 0~.)GG%R>D
z (#Xca
C zpsqTQ
public TestMethod() VVN# $
{ ///xx/weblogic60b2_win.exe A?sNXhh
try{ g\j>qUjs%Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); g1dmkX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :+1bg&wQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); JOgmF_(>Z
fileFetch.start(); f-s~Q4
} kI]=&Rw
catch(Exception e){e.printStackTrace ();} {"}+V`O{
7(5]Ry:
yHtGp%j
} 8tC+ lc
(V^QQ !:
[BE:+ ID3
public static void main(String[] args) )_F(H)*
{ X%35XC.n
new TestMethod(); & ]%\.m
} 6i^0T
} ~CulFxu
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