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)); Ys3C'Gc
} G:&Q)_
for(int i=0;i<nEndPos.length-1;i++) l{pF^?K
{ Z$hxo)|
nEndPos = nStartPos[i+1]; U)l>#gf8
} /KV@Ce\
nEndPos[nEndPos.length-1] = nFileLength; dkn_`j\v
} B"B
} ^|\?vA
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,}|V'y
//启动子线程 ?<}qx`+%Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'V>+G>U
for(int i=0;i<nStartPos.length;i++) d z\b]H]
{ Wex4>J<`/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ypifXO;m7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iH$N HfH
nStartPos,nEndPos,i); Uis P 8/k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X>B/DT
fileSplitterFetch.start(); Ebk@x=E
} pucHB<R@bL
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V\xQM;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?nn,RBS-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J *B`C^i
nEndPos = " + nFileLength); _Ey8P0-I
// fileSplitterFetch[nPos.length-1].start(); WUV Q_<i+
M<L<mP}
i@;a%$5
//等待子线程结束 D"WkD j"M
//int count = 0; tvH)I px
//是否结束while循环 \G"/Myi
boolean breakWhile = false; g ` {0I[
}9kq?
tO0+~Wm
while(!bStop) }hf*Jw
{ =0-qBodbl
write_nPos(); H9Z3.F(2
Utility.sleep(500); E:tUbWVp
breakWhile = true; Q6>vF)( -
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eyG.XAP
for(int i=0;i<nStartPos.length;i++) 0VZj;Jg}q
{ m6gr!aT
if(!fileSplitterFetch.bDownOver) (Zn\S*_@/
{ %2+]3h>g
breakWhile = false; @rF\6I
break; u`~{:V
} GhT7:_r~
} th<]L<BP/
if(breakWhile) CNz[@6-cYU
break; ;wF|.^_2
yUG5'<lX
kr/h^e
//count++; loB/w{r*x
//if(count>4) ,jWd?-NH
// siteStop(); X>4`{x`
} -jy"?]ve.
Rju8%FRO
&Y>u2OZ
System.err.println("文件下载结束！"); -$q/7,os
} ig,|3(
catch(Exception e){e.printStackTrace ();} vOS0E^
} 5zGj,y>u
aVb]H0
nXS%>1o,
//获得文件长度 525>=h
public long getFileSize() pSP_cYa#(#
{ KWUz]>Z
int nFileLength = -1; )X/Faje
try{ *X #e
URL url = new URL(siteInfoBean.getSSiteURL()); ^m=%Ctu#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P(;c`
httpConnection.setRequestProperty("User-Agent","NetFox"); ,W-0qN&%/
X3nhqQTZ
SMFW]I2T/
int responseCode=httpConnection.getResponseCode(); $5IrM7i
if(responseCode>=400) QhUraZ
{ 75HL
processErrorCode(responseCode); f0s &9H
return -2; //-2 represent access is error EHHxCq?
} H^g<`XEgw
C] w< &o
6~S0t1/t?
String sHeader; (`u!/
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%},gE[N!J
for(int i=1;;i++) o;mIu#u
{ o0L#39`'g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A]9JbNV
//Utility.log(in.readLine()); bAiw]xi
sHeader=httpConnection.getHeaderFieldKey(i); Om
if(sHeader!=null) q9!9OcN2
{ l/^-:RRNKi
if(sHeader.equals("Content-Length")) 8957$g
{ v~Qy{dn P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zTB9GrU
break; E2|iAT+=.
} obq}#
} M<unQ1+wh
else +a-@ !J~:
break; xW =$j|
} Ol[gck|~
} o}A #-
catch(IOException e){e.printStackTrace ();} ea0tx3'
catch(Exception e){e.printStackTrace ();} zIFL?8!H9{
N -]PK%*
.}N^AO=
Utility.log(nFileLength); D8Rmxq!
PNgMLQI6
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return nFileLength; a`*WpP\+
} :$aW@?zAY
[r8 d+
MF}Lv1/[-J
//保存下载信息（文件指针位置） ?8@*q6~8
private void write_nPos() C4tl4df9
{ E{s|#
try{ l|A8AuO*?
output = new DataOutputStream(new FileOutputStream(tmpFile)); Mqp68%
output.writeInt(nStartPos.length); (dF;Gcw+
for(int i=0;i<nStartPos.length;i++) #\BI-zt
{ ?w/nZQWi
// output.writeLong(nPos); r5!M;hU1j
output.writeLong(fileSplitterFetch.nStartPos); F |81i$R
output.writeLong(fileSplitterFetch.nEndPos); +c`C9RXk
} ~4MjJKzA
output.close(); RCYbRR4y
} "n }fEVJ,
catch(IOException e){e.printStackTrace ();} Q+(:n)G_6E
catch(Exception e){e.printStackTrace ();} 2bnIT>(
} X#,[2&17Fh
7 afA'.=
-Y?(Zz_w
//读取保存的下载信息（文件指针位置） KHz838C]
private void read_nPos() dY@Tt&k8E
{ ]wpYxos
try{ +A?+G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L"7` \4
int nCount = input.readInt(); a=.db&;vY
nStartPos = new long[nCount]; V C'-h~
nEndPos = new long[nCount]; OW}j4-~wL
for(int i=0;i<nStartPos.length;i++) oy bzD
{ w9<FX>@
nStartPos = input.readLong(); f^sb0nU
nEndPos = input.readLong(); HcVs(]tIW
} F>kn:I"X)
input.close(); +1jqCW
} AJlIA[Kt:
catch(IOException e){e.printStackTrace ();} k`mrRs
catch(Exception e){e.printStackTrace ();} 8sF0]J[g{
} ;To+,`?E;q
@-@rG>y^:
rbun5&RCyW
private void processErrorCode(int nErrorCode) gc7:Rb^E5t
{ Rn(F#tI
System.err.println("Error Code : " + nErrorCode); SA 4je9H%
} 2mU-LQ1WN
zGd*Q5l
T.PZ}4
//停止文件下载 |ezO@
public void siteStop() mRnzP[7-\)
{ V'f5-E0
bStop = true; F"f}vl
for(int i=0;i<nStartPos.length;i++) IA 9v1:>
fileSplitterFetch.splitterStop(); >\x_"oR
G%8)6m'3
`pAp[]SfQd
} _&Uo|T
} MY*>)us\
//负责部分文件的抓取 obc^<ZD]
**FileSplitterFetch.java j X!ftm2
*/ 7U )qC}(
package NetFox; \v P2B
0R5^p
2td|8vDA
import java.io.*; -kri3?Y,
import java.net.*; l)PFzIz=V
vua1iN1
aco}pXz
public class FileSplitterFetch extends Thread { e9hVX[uq
6dR-HhF
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String sURL; //File URL 9c5G6n0
long nStartPos; //File Snippet Start Position ah"MzU)
long nEndPos; //File Snippet End Position KYmWfM3^
int nThreadID; //Thread's ID M|E2&ht
boolean bDownOver = false; //Downing is over 19w,'}CGk
boolean bStop = false; //Stop identical bb0McEQy
FileAccessI fileAccessI = null; //File Access interface A"<)(M+kG
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lp0T\ %
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]7R&m)16
{ nK%/tdq
this.sURL = sURL; n.Eoi4jV'
this.nStartPos = nStart; {L-aXe{
this.nEndPos = nEnd; a(43]d&
nThreadID = id; i_'R"ob{S
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `ToRkk&&>{
} k1Mxsd
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#b"5L2D`y'
public void run() sHPwW5j/o'
{ 0jJ28.kOp
while(nStartPos < nEndPos && !bStop) zTBi{KrZ
{ "G-0iKW;
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b^l -*4
try{ ]T3BDgu%&
URL url = new URL(sURL); )3`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <.7I8B7
httpConnection.setRequestProperty("User-Agent","NetFox"); #nf%ojh
String sProperty = "bytes="+nStartPos+"-"; B[/['sD
httpConnection.setRequestProperty("RANGE",sProperty); LY88;*:S
Utility.log(sProperty); e<O;pM:
Fb{`a[&
HSr"M.k5
InputStream input = httpConnection.getInputStream(); kSDa\l!W]
//logResponseHead(httpConnection); NtA|#"^
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Z>w^j.(
byte[] b = new byte[1024]; vrm{Ql&
int nRead; j zmSFKg*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \`Ph=lJO
{ 6aF'^6+a
nStartPos += fileAccessI.write(b,0,nRead); k.=S+#"}
//if(nThreadID == 1) (|a$N.e&K
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q!2iOvK
} Puth8$
sAjKf\][
c]aK N
Utility.log("Thread " + nThreadID + " is over!"); Xx y Bg!R
bDownOver = true; & L.PU@
//nPos = fileAccessI.write (b,0,nRead); XC/]u%n8](
} X\3,NR,
catch(Exception e){e.printStackTrace ();} |!xfIR>=F
} [`zbf_RyO
} =S[FJaIu7
6Er0o{iI
e2-70UvW^
//打印回应的头信息 (9YYv+GGd*
public void logResponseHead(HttpURLConnection con) |<$<L`xoe
{ O2'bNR
for(int i=1;;i++) ll<9f)
{ z7t'6Fy9'
String header=con.getHeaderFieldKey(i); ;oY(I7
if(header!=null) s7UhC.>'@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JJ N(M*;
Utility.log(header+" : "+con.getHeaderField(header)); BudWbZ5>Ep
else we H@S
break; A}#]g>L
} |?fW!y
} CNpe8M=/3
=ve*g&
z7@(uIl=X
public void splitterStop() (Xr_ np @
{ ENYF0wW
bStop = true; 9#EHXgz
} Q0L@.`~
DQ n`@
)ZgER[
} P"V{y|2
,.6J6{
}W__ffH
/* J2oWssw"
**FileAccess.java dY4k9p8
*//文件访问(定位，写) lZS_n9Sc
package NetFox; +C'TW^
import java.io.*; >TlW]st
bQ^DX `o6P
p29yaM
public class FileAccessI implements Serializable{ ,{uW8L
6HEqm>Yau
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C`yvBt40r
RandomAccessFile oSavedFile; 'd2qa`H'}B
long nPos; }:RT,<
%EJ\|@N:
pT3X/ra
public FileAccessI() throws IOException {w |dM#
{ &sZ9$s:(^
this("",0); zldfRo\wl
} )y%jLiQv
]< s\V-y
R%Ui6dCLo
public FileAccessI(String sName,long nPos) throws IOException `FzYvd"N
{ d4y9AE@k
oSavedFile = new RandomAccessFile(sName,"rw"); n2xLgK=
this.nPos = nPos; s.R-<Y3
oSavedFile.seek(nPos); 68koQgI[^
} ( K6~Tj
`x{.z=xC
Sc4obcw%
public synchronized int write(byte[] b,int nStart,int nLen) 3wN?|N
{ L(WL,xnBy
int n = -1; <THZ2`tTK3
try{ d}{LM!s
oSavedFile.write(b,nStart,nLen); Ci7P%]9
n = nLen; `2xH7a-
} %1-K);SJ
catch(IOException e) sJ))<,e5I
{ h&=O-5
e.printStackTrace (); v"P&`1=T
} D00G1:Ft(T
P"(z jG9-
^CZCZ,v
return n; H&w:`JYDL3
} \)OZUch
u*t,i`
NJ;"jQ-
} z-EwXE
0>,.c2),
g>2aIun_Q
/* GVmC }>z
**SiteInfoBean.java 0bMoUy*q
*/ fD1?z"lo
package NetFox; ;y>S7n>n:
O1GDugZ
~L-0~
public class SiteInfoBean { A}t%;V2
NFk}3w:
)E'Fke
private String sSiteURL; //Site's URL $&cz$jyY
private String sFilePath; //Saved File's Path :J^qjAV
private String sFileName; //Saved File's Name k:b/Gq`
private int nSplitter; //Count of Splited Downloading File S~KS9E~\
aq3~!T;W
3lo;^KX !
public SiteInfoBean() z]^+^c_
{//nSplitter的缺省值为5 D Irgq|8
//default value of nSplitter is 5 96(R'^kNX
this("","","",5); QBy{|sQ`
} R/^@cA
K(<$.
8zhBA9Y#~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y }\r#"Z`
{ x^A7'ad0
sSiteURL= sURL; !Y (apVQ
sFilePath = sPath; t#C,VwMe[
sFileName = sName; !Eq#[Gs
this.nSplitter = nSpiltter; <d5@CA+M
o^3FL||P#r
>(X#<`
} ` ^DjEdUN
rwiw Rh
`E@kFJ(<On
public String getSSiteURL() =M7TCE
{ EXuLSzQwv
return sSiteURL; k`Nyi)AGe
} lC0~c=?J
Q"40#RFA
O~V1Ywfq7^
public void setSSiteURL(String value) A (Bk@;
{ > 2#%$lX6
sSiteURL = value; '"y}#h__T
} Yc^%zxub
-<_QF82
6?N4l ]l
public String getSFilePath() O|QUNr9
{ >R!"P[*
return sFilePath; "!O1j r;
} |^R*4;Phe
((XE\V\}Z
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public void setSFilePath(String value) / s,tY74'5
{ Hkdf$$\
sFilePath = value; B`fH^N
} 2nv[1@M
hk%k(^ekU]
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public String getSFileName() t8QRi!\=
{ F|>05>8
return sFileName; |( G2K'Ab
} U@'F%nHw
owvS/"@
fAGctRGH
public void setSFileName(String value) \R(R9cry
{ w/W7N
sFileName = value; \<~}o I
} N2BI_,hI1
#uSK#>H_!
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public int getNSplitter() wd[eJcQ,
{ LXj5R99S
return nSplitter; 8$0\J_
} r`jWp\z
%Tv^GP{}
gY(1,+0-
public void setNSplitter(int nCount) `0{ S3v
{ y`yZR _
nSplitter = nCount; kbYeV_OwM
} Bq@zaMv
} iib
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pj0fM{E
/* S,''>`w
**Utility.java $IVwA
*/ "X04mQn15
package NetFox; oKA&An
r3qf[?3`6
a8pY[)^c
public class Utility { ](#&.q%5!
j(eFoZz,
P`S@n/}
public Utility() +f>cxA
{ <xo-Fv
*/z??fI27
Dzl;-]S
} o%`Xa#*Ly
im]g(#GnKh
//线程睡眠 G,XPT,:%
public static void sleep(int nSecond) H6K`\8/SeN
{ )}MHx`KT2
try{ WA6!+Gy
Thread.sleep(nSecond); O/Rhf[7v*
} $bvJTuw
catch(Exception e) ,lt8O.h-l
{ t9^A(Vh"-
e.printStackTrace (); uLQ
} =WG=C1Z
} EHn"n"Y
I7n3xN&4"
//日志 ,qQG;w,m
public static void log(String sMsg) #Yuvbb[
{ geM6G$V&
System.err.println(sMsg); RO&H5m r%@
} EpYy3^5d
UG;Y^?Ppe5
x;LzG t:w
public static void log(int sMsg) ?+0GfIV
{ At6qtoPRA
System.err.println(sMsg); X[](Kj^`<
} nXA\|c0
} QAPu<rdJP
WC,+Cn e
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/* X^@I].
**TestMethod.java 17|np2~
*/ amWD-0V
package NetFox; zR;X*q"T$4
?4 S+edX
QA#3bFZt1n
public class TestMethod { (=4W-z7
ytz SAbj
"*z_O
public TestMethod() @U{<a#
{ ///xx/weblogic60b2_win.exe :hRs`=d"r
try{ Ju2l?RrX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b:J(b?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q=uRKh
SiteFileFetch fileFetch = new SiteFileFetch(bean); T?Fcohz(
fileFetch.start(); FV39QG4b4
} 4|?{VQ
catch(Exception e){e.printStackTrace ();} BvD5SBa}"
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Y&HK1>M_
} &HW1mNF9
X2|Y
N8r*dadDd
public static void main(String[] args) w Y
{ SqA J-_~
new TestMethod(); w|[RDaAb
} ^].jH+7i*
} kq=V4-a[
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