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)); l^tRy_T:-
} yEB#*}K?
for(int i=0;i<nEndPos.length-1;i++) \1?'JdN
{ 8fQfu'LyjY
nEndPos = nStartPos[i+1]; c;KMox/
} tw 3zw`o:
nEndPos[nEndPos.length-1] = nFileLength; &n?RKcH}d
} q(EN]W],
} yz>S($u
kg(}%Ih
^0{t
//启动子线程 |d\1xTBLp
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5l,Lp'k
for(int i=0;i<nStartPos.length;i++) Q4Wz5n1yp7
{ ( ?e Et&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f\hQ>MLzt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oG hMO
nStartPos,nEndPos,i); B)d 4]]4\\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B}zBbB
fileSplitterFetch.start(); |A|K);
} giIPK&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y9T5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `S3)uV]I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FBrh!vQ<
nEndPos = " + nFileLength); =yRv*C
// fileSplitterFetch[nPos.length-1].start(); ]l=CiG4!M
+s7w@
lkp$rJ#6
//等待子线程结束 ?hrz@k|
//int count = 0; RP 6<#tq,
//是否结束while循环 c[3x>f0
boolean breakWhile = false; $E8}||d
re4z>O*
(B*,|D[J@i
while(!bStop) IW}Wt{'m
{ 2h@&yW2j
write_nPos(); ,l,q;]C%
Utility.sleep(500); iTT7<x
breakWhile = true; =|fB":vk
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<jaQ0S{|
for(int i=0;i<nStartPos.length;i++) xMpgXB!'
{ l%u8Lq
if(!fileSplitterFetch.bDownOver) mtLiS3Nk8
{ V~-tp^
breakWhile = false; R%9,.g<
break; }dU!PZ9N)
} 4,=;:#n,J
} 6!Mm")
if(breakWhile) k O.iJcZg
break; tQ.H/;
fCX8s(|F
gTLBR
//count++; c:B` <
//if(count>4) )g^O'e=m
// siteStop(); 5CfD/}{:#I
} p%#'`*<a_
g">^#^hBE
[{>1wJ Pdj
System.err.println("文件下载结束！"); rzvKvGd#N
} r&F 6ZCw
catch(Exception e){e.printStackTrace ();} `Hu2a]e9
} Vkf{dHjW
?1LRR ;-x
(bB"6 #TI
//获得文件长度 9pWSvalw9
public long getFileSize() B)P]C5KRD
{ {([`[7B>a<
int nFileLength = -1; >4+KEK
try{ <29K! [
URL url = new URL(siteInfoBean.getSSiteURL()); wL>;_KdU`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5-&"nn2*}1
httpConnection.setRequestProperty("User-Agent","NetFox"); P%!=Rj^2m
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{/,AMJ<:G]
int responseCode=httpConnection.getResponseCode(); 1FT3d
if(responseCode>=400) $++O@C5
{ p|BoEITL
processErrorCode(responseCode); Tv 5J
return -2; //-2 represent access is error bUYjmb2g)
} V"}Jsr
Ua=r24fy
m4'jTC$
String sHeader; O,NVhU7,
(I35i!F+tY
YPCitGBl
for(int i=1;;i++) B`jq"[w]-
{ 3Y&4yIx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GY^;$?
//Utility.log(in.readLine()); &rl;+QS
sHeader=httpConnection.getHeaderFieldKey(i); [%~yY&
if(sHeader!=null) lJT"aXt'M
{ $~%h4
if(sHeader.equals("Content-Length")) j"VDqDDz
{ lWT`y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d9%P[(yM^
break; :AI%{EV-L
} ( 5uSqw&U
} /{W6]6^
else ;BKU _}k=
break; )8SWU)/
} ,(f W0d#
} j0(jXAc;UB
catch(IOException e){e.printStackTrace ();} JO90TP $
catch(Exception e){e.printStackTrace ();} WJ[>p ELT,
=);@<Jp
)OVa7[-T
Utility.log(nFileLength); nr,Z0
1X9s\JKQ
jp^Sw|
return nFileLength; ]]3rSXs2}J
} (mKH,r
X>P|-n#
yf4L0.
//保存下载信息（文件指针位置） U4yl{?
private void write_nPos() ='m%Iq7X
{ ()F{kM8
try{ 5NH4C
output = new DataOutputStream(new FileOutputStream(tmpFile)); ItZYOt|Hn
output.writeInt(nStartPos.length); x}V&v?1{5
for(int i=0;i<nStartPos.length;i++) =;b3i1'U
{ +%u3% }
// output.writeLong(nPos); e?*Teb?R
output.writeLong(fileSplitterFetch.nStartPos); cUdS{K&K
output.writeLong(fileSplitterFetch.nEndPos); %\n|2*r
} 4RYH^9;>K
output.close(); r\Yh'cRW{
} cO5zg<wF
catch(IOException e){e.printStackTrace ();} m8e()8lZ3
catch(Exception e){e.printStackTrace ();} Xtz:^tg
} 5,g +OY=\
tMp!MQ
n|XheG7:
//读取保存的下载信息（文件指针位置） U V*Ruy-
private void read_nPos() -B&(&R
{ %Ta"H3ZW
try{ ~(kqq#=s
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w`V6vYd@
int nCount = input.readInt(); 't0M+_J
nStartPos = new long[nCount]; "J=Cy@SSa
nEndPos = new long[nCount]; 1EEcNtpub]
for(int i=0;i<nStartPos.length;i++) hh&$xlO)(v
{ pt,L
nStartPos = input.readLong(); aekke//y
nEndPos = input.readLong(); |?8nO.C~V
} Jou*e%
input.close(); l:uQ#Z)
} +>K&zS
catch(IOException e){e.printStackTrace ();} Qz#By V:
catch(Exception e){e.printStackTrace ();} VJ&<6
} 'wG1un;t
!*NDsC9
|D"L!+J-$
private void processErrorCode(int nErrorCode) ipbhjK$
{ Y%;X7VxU*
System.err.println("Error Code : " + nErrorCode); FpA t
} >(S)aug$1
%oTBh*K'o
P=jsOuW
//停止文件下载 'yq?xlIj
public void siteStop() 1BU97!
{ $5)#L$!,]
bStop = true; YZ4`b-
for(int i=0;i<nStartPos.length;i++) n9}BT^4 v
fileSplitterFetch.splitterStop(); WcNQF!f
Babzrt-
8Sj<,+XFq
} UNa"\
} ":M]3.
//负责部分文件的抓取 tjb$MW$('
**FileSplitterFetch.java dR1IndZl
*/ u@#%SX
package NetFox; ,#3Aaw
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{/,(F^T>2
import java.io.*; $Z#~wsw
import java.net.*; 'WP~-}(
nLz;L r!
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public class FileSplitterFetch extends Thread { !6=;dX
Jj>Rzj!m
-6kX?sNl)X
String sURL; //File URL D!,5j_,j%
long nStartPos; //File Snippet Start Position ~Dq-q6-@t
long nEndPos; //File Snippet End Position 1Ys=KA-!_x
int nThreadID; //Thread's ID M*gvYo
boolean bDownOver = false; //Downing is over 04Zdg:[3-!
boolean bStop = false; //Stop identical fGlvum
FileAccessI fileAccessI = null; //File Access interface ="& GU%$
~ O#\$u
%QEBY>|lI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p;}`PW
{ 6LCtWX
this.sURL = sURL; Eb[;nk?
this.nStartPos = nStart; PljPhAce
this.nEndPos = nEnd; :a;F3NJ
nThreadID = id; ?;~E*kzO&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 k}fC58q
} JT0j2_*Rr
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7gf(5p5ZV
public void run() :k1?I'q%
{ _F6<ba}o3
while(nStartPos < nEndPos && !bStop) Gkuqe3
{ '=E;^'Rl
V*\hGNV
/ZV2f3;t
try{ U|Fqna
URL url = new URL(sURL); )mm0PJF~q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $uTrM8
httpConnection.setRequestProperty("User-Agent","NetFox"); (2H GV+Dg
String sProperty = "bytes="+nStartPos+"-"; 6}E>B{Y
httpConnection.setRequestProperty("RANGE",sProperty); 1(BLdP3&
Utility.log(sProperty); #G]IEO$M6
;99oJD,
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InputStream input = httpConnection.getInputStream(); Ak@!F6~
//logResponseHead(httpConnection); Hj{.{V
b:F;6X0~Hl
#[=kQ&
byte[] b = new byte[1024]; &B(z**+9
int nRead; n5d8^c!2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gd0)s1{9
{ <K^a2 D
nStartPos += fileAccessI.write(b,0,nRead); PSq?8.
//if(nThreadID == 1) 2QaE&8vW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w~6UOA8}
} s;TB(M~i[
B.G6vx4yp
5m~9Vl-&
Utility.log("Thread " + nThreadID + " is over!"); \bdKLcKI,
bDownOver = true; {4 Yxh8
//nPos = fileAccessI.write (b,0,nRead); 7e+C5W*9b
} rlKR <4H
catch(Exception e){e.printStackTrace ();} BZW03e8|
} N[W#wYbH
} s*Qyd{"z
XF(D%ygeC
4O-LLH
//打印回应的头信息 b+qd' ,.Z
public void logResponseHead(HttpURLConnection con) $}su'EIo
{ o.!o4&WH
for(int i=1;;i++) tR>zBh_b
{ }BC%(ZH6
String header=con.getHeaderFieldKey(i); ExtC\(X;
if(header!=null) >)M1X?HI5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zF`a:dD$d
Utility.log(header+" : "+con.getHeaderField(header)); Kb+SssF
else ~o_JZ:
break; .*`^dt
} "e"#k}z9
} 5c::U=
l[i4\ CT
F62 uDyY
public void splitterStop() mce qZv
{ oVK:A;3T|
bStop = true; 3/]1m9x
} y\_+,G0
/o4e n
[mv? \HDa~
} SN@>mpcJS
.Qrpz^wdt
`C: 7N=9
/* >niv>+!N
**FileAccess.java %/I:r7UR{
*//文件访问(定位，写) m OUO)[6y
package NetFox; P+f}r^4}
import java.io.*; Mbxl{M >
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public class FileAccessI implements Serializable{ h.K"v5I*
a&JY x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2gO@
RandomAccessFile oSavedFile; C0f%~UMwd
long nPos; 4eB'mPor
E\D,=|Mul
nmiJ2edx
public FileAccessI() throws IOException )zO|m7
{ >/\TG8t,f
this("",0); By6O@ .\V
} Zocuc"j
r1 :TM|5L
qZ!kVrmg&
public FileAccessI(String sName,long nPos) throws IOException NB<8M!X/
{ <VD7(j]'^
oSavedFile = new RandomAccessFile(sName,"rw"); BC!) g+8
this.nPos = nPos; KC}G_"f.$
oSavedFile.seek(nPos); &Y1h=,KR9
} <xeB9
pBe1:
(5] [L<L
public synchronized int write(byte[] b,int nStart,int nLen) Vf:.C|Z
{ $s=` {vv
int n = -1; .X3n9]
try{ OP+*%$wR
oSavedFile.write(b,nStart,nLen); 9~=zD9,|iA
n = nLen; yHE\Q
} 6t7FklM%
catch(IOException e) l4$ sku-
{ 'V%w{ZiiV
e.printStackTrace (); >x%HqP#_V
} 'eBD/w5U
'%/=\Q`
e%pohHI
return n; (t3gNin
} #@-dT,t
&;?+ ^L>
wM[Z 0*K
} D8! Y0
5q@s6_"{
4P?`<K'
/* Q'jGNWep
**SiteInfoBean.java I-8I/RRkmP
*/ z l`m1k-X
package NetFox; mI<sf?.
7./WS,49
=/j!S|P
public class SiteInfoBean { QsKnaRT
RLex#j
9ec?L
private String sSiteURL; //Site's URL e~*tQ4
private String sFilePath; //Saved File's Path A#']e8
private String sFileName; //Saved File's Name LtwfL^#
private int nSplitter; //Count of Splited Downloading File D]fgBW-
fzVN;h
&b,A-1`w_
public SiteInfoBean() kz}Bc F
{//nSplitter的缺省值为5 Pbbi*&i
//default value of nSplitter is 5 .KG9YGL#
this("","","",5); P//nYPyzg
} f'"PQr^9
N!<l~[rc
!|V_DsP
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8cvSA&l(D
{ cGo_qR/B(>
sSiteURL= sURL; Ui"$A/
sFilePath = sPath; WoNJF6=?
sFileName = sName; @\gE{;a8
this.nSplitter = nSpiltter; mHW%^R=
+>eX1WoTy
nfZe"|d
} ^vVAuO
sqF.,A,
-;6uN\gq
public String getSSiteURL() FeZWS>N
{ 6^jrv [d
return sSiteURL; ]!1HN3
} ~#so4<A`3
Q$:,N=%
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public void setSSiteURL(String value) /_expSPHl
{ F#Pn]
sSiteURL = value; * #z@b
} Ap"%%D^{:
zA|lbJz=GY
L`O7-'`
public String getSFilePath() ow`F 7
{ ; %AgKgV
return sFilePath; \%}]wf}
} (}T},ygQ
D>U(&n
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public void setSFilePath(String value) 6v}q @z
{ c9nv=?/}f
sFilePath = value; OFcP4hDi
} 2.@IfBF6
'tQp&pj
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public String getSFileName() C[ KMaB
{ wwR}h I(
return sFileName; 8WQc8
} })PU`?f
(bNoe(<qU
4}0YLwgJ
public void setSFileName(String value) /UR;,ts
{ p? VDBAx
sFileName = value; A3q#,%
} |{%$x^KyJ
vkYiO]y
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public int getNSplitter() Y@Ry oJ
{ ;3Z?MQe"NQ
return nSplitter; &`]T#">
} R:^jQ'1
ZRr.kN+F
Sq2 8=1%
public void setNSplitter(int nCount) ]_!NmB_3
{ VS~+W=5}
nSplitter = nCount; Nd;pkssd
} HB<>x
} * +6Z^7
= ~*Vfx
r0\C2g_X
/* $RC)e7
**Utility.java olHmRJ
*/ VhnIr#L+
package NetFox; NJ$Qm.S
0uGTc[^^M
c[vFh0s"m
public class Utility { ?ZhBS3L
;<F^&/a|yQ
t`eIkq|NxI
public Utility() LS-_GslE7\
{ ^7:UC\_
[*H h6
G]Im.x3O-
} J'I1NeK
(@*%moo
//线程睡眠 gla'urb[i|
public static void sleep(int nSecond) {"N:2
{ |*8X80<
try{ Pvm pWa
Thread.sleep(nSecond); G}]'}FUp
} TTo?BVBK
catch(Exception e) ]4FAbY2'h
{ 3]&le[.
e.printStackTrace (); kFfNDM#D
} x|Ms2.!
} YEB7X>p#
Pn?gB}l
//日志 4~d:@Gmk&
public static void log(String sMsg) \5HVX/
{ sr<\fW
System.err.println(sMsg); raMtTL+
} >Gvd?r
)L"J?wTe
?uF3Q)rCk
public static void log(int sMsg) |g<l|lqz|
{ GIS,EwA
System.err.println(sMsg); h;OHpvk
} Lr "V
} >5t]Zlb`
\`*]}48Z
2Fbg"de3-
/* _|COnm
**TestMethod.java Yg;7TKy
*/ +4[Je$qYa
package NetFox; u*T#? W?
"(p&Oz
z;&J9r$`
public class TestMethod { QC1\Sn/
@8cn<+"b
@Fb 2c0?Y
public TestMethod() U6YQ*%mZ_
{ ///xx/weblogic60b2_win.exe d(,M
try{ V'l9fj*E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]-w.x]I
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '*K%\]
SiteFileFetch fileFetch = new SiteFileFetch(bean); =o[H2o y
fileFetch.start(); 1f$1~5Z
} jZ<f-Ff0
catch(Exception e){e.printStackTrace ();} b C"rQJg
v;s^j
R]d934s
} YG#{/;^nm)
h-%RSei5
DV!0zzJ
public static void main(String[] args) )kE1g&
{ [tJp^?6*
new TestMethod(); Tqx
} PWS5s^WM
} LUA<N:
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