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)); FtF!Dtv
} =z@'vu$Fh
for(int i=0;i<nEndPos.length-1;i++) ";>D0h^D
{ Jl^oDW
nEndPos = nStartPos[i+1]; 8zpK;+
} 'TbA^U[
nEndPos[nEndPos.length-1] = nFileLength; 4NEk#n
} W<9GwMU
} T!;<Fy"p
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//启动子线程 j*6!7u.,K
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; R6M@pO
for(int i=0;i<nStartPos.length;i++) ]|732Z
{ {fX4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4CN8>J'-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zu;Yw=cM)
nStartPos,nEndPos,i); ^_<pc|1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IA+>dr
fileSplitterFetch.start(); E!Ng=}G&_
} 33u7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QZwRg&d<o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }D=h"\_=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `Cb$8;)z
nEndPos = " + nFileLength); f[ER`!
// fileSplitterFetch[nPos.length-1].start(); tv;3~Y0i
-7+Fb^"L
X^@d@xU4v
//等待子线程结束 }B]FHpi
//int count = 0; pXQ&2s$
//是否结束while循环 ^Jkj/n'
boolean breakWhile = false; -D V;{8U4
xt`znNN
Ezml LFp.
while(!bStop) Ni0lj:
{ p=r{ODw#3
write_nPos(); | _S9U|
Utility.sleep(500); C8{CKrVE
breakWhile = true; RF6|zCWuI
V];RQWs
L9AfLw5&X
for(int i=0;i<nStartPos.length;i++) Dd{{d?;B
{ ev+NKUi=
if(!fileSplitterFetch.bDownOver) #Io#OG<7b
{ ||_F /AD
breakWhile = false; >|rL0
break; ^Cak/5^K
} A"P1B]
} d3 N %V.w
if(breakWhile) 5aWKyXBIx
break; z&-`<uV~
''WX
I5D\Z
//count++; 0\gE^=o[
//if(count>4) w$t2Hd
// siteStop(); f,?7,?x
} '7=*n_l
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System.err.println("文件下载结束！"); %EVg.k$
} OZv&{_b_
catch(Exception e){e.printStackTrace ();} ](0A/,#q6
} S@*@*>s^
ll5Kd=3
hpw;w}m
//获得文件长度 Gge"`AT
public long getFileSize() E]7G4
{ /_56H?w\
int nFileLength = -1; +nqOP3
try{ JUXK}0d%eN
URL url = new URL(siteInfoBean.getSSiteURL()); o= 8yp2vG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ',CcLN
httpConnection.setRequestProperty("User-Agent","NetFox"); AM}OLHj
%_3{Db`R>
Lh. L~M1X
int responseCode=httpConnection.getResponseCode(); "iKK&%W
if(responseCode>=400) CP?\'a"Kt
{ u(lq9; ;Th
processErrorCode(responseCode); ()SG
return -2; //-2 represent access is error koie
} X'3F79`
6: M
;aFQP:l/
String sHeader; Dbtw>:=
I4");T3
JEAqSZak#
for(int i=1;;i++) Z2LG/R
{ {!EbGIh
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \K)q$E<!
//Utility.log(in.readLine()); v/m6(z
sHeader=httpConnection.getHeaderFieldKey(i); ,Wdyg8&.
if(sHeader!=null) nH_A`m3%/
{ +q2l,{|?
if(sHeader.equals("Content-Length")) ricDP 9#a
{ CBF>157B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >o[T#U
break; #ob">R
} hxtu^E/
} >M +!i+
else (*M(gM{;
break; T&{EqsI=B
} M,6AD]
} $AX!L+<!
catch(IOException e){e.printStackTrace ();} u4Xrvfb,
catch(Exception e){e.printStackTrace ();} ZBnf?fU
1f~DUku=
2R1W[,Ga!
Utility.log(nFileLength); N,;Bl&EU
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b.t]p
return nFileLength; G.BqT\ o'
} sDwSEg>#B
9EH%[wfv
V1Fdt+#
//保存下载信息（文件指针位置） T0Gu(c`1d
private void write_nPos() *=ALns?y
{ apYf,"|9
try{ [NuayO3
output = new DataOutputStream(new FileOutputStream(tmpFile)); RLIugz{IH
output.writeInt(nStartPos.length); i.'f<z$<
for(int i=0;i<nStartPos.length;i++) L>PpXTWwy
{ gfp#G,/B
// output.writeLong(nPos); `5gcc7b
output.writeLong(fileSplitterFetch.nStartPos); x JepDCUJ>
output.writeLong(fileSplitterFetch.nEndPos); dpE+[O_
} ]6(NeS+
output.close(); A\?O5#m:$
} {0[qERj"z
catch(IOException e){e.printStackTrace ();} *W0`+#Dcv
catch(Exception e){e.printStackTrace ();} DsP+#PX
} @F=4B0=
W"~G]a+
rK`*v*
//读取保存的下载信息（文件指针位置） /FQumqbnt
private void read_nPos() gsZCWT
{ 2B*9]AHny
try{ JNsK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ")8wu1V-
int nCount = input.readInt(); _p90Zm-3X
nStartPos = new long[nCount]; jaDZPX-yS
nEndPos = new long[nCount]; H7R1GaJ
for(int i=0;i<nStartPos.length;i++) K.1#cf ^'
{ pfZxG.l
nStartPos = input.readLong(); bhFzu[B
nEndPos = input.readLong(); o05) I2
} WSh+5](:
input.close(); qf'uXH
} ]xFd_OHdb
catch(IOException e){e.printStackTrace ();} @(ev``L5g
catch(Exception e){e.printStackTrace ();} 4|*_mC
} A}W&=m8!
,(]hykbXp
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private void processErrorCode(int nErrorCode) m'a3}vRV(
{ o^lKM?t
System.err.println("Error Code : " + nErrorCode); [P"#?7 N
} p>!`JU`{?
(m@({
F_@PSA+
//停止文件下载 *)"`v]
public void siteStop() qex.}[
{ "Z#&A
bStop = true; I]zCsT.
for(int i=0;i<nStartPos.length;i++) )|*HkdF`
fileSplitterFetch.splitterStop(); QQ pe.oF
{E>kFeg
3F<My+J
} ;i\i+:=
} 9.>v ;:vL
//负责部分文件的抓取 c7sW:Yzil
**FileSplitterFetch.java T?Hs_u{
*/ P1)9OE
package NetFox; S_1R]n1/
$+ lc;N
&;*jMu6
import java.io.*; &i6WVNGy
import java.net.*; k;q|pQ[
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c"6<p5j!
public class FileSplitterFetch extends Thread { U Tw\_s
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String sURL; //File URL BgUf:PT
long nStartPos; //File Snippet Start Position )ASI41
long nEndPos; //File Snippet End Position Gi?"
int nThreadID; //Thread's ID t13wQt
boolean bDownOver = false; //Downing is over ax,%07hJ
boolean bStop = false; //Stop identical U^:+J-z{
FileAccessI fileAccessI = null; //File Access interface CH!Lf,G
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "Q-TLN5(
{ c]#F^(-A`
this.sURL = sURL; ub7|'+5
this.nStartPos = nStart; T =_Hd
this.nEndPos = nEnd; wwk=*X-8
nThreadID = id; 5Z1b9.;.,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y!"LrkC
} 0c /xE<h
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public void run() ):kDWc
{ l/#;GYB]
while(nStartPos < nEndPos && !bStop) 48W$,
{ p^MV<}kk
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try{ L;wzvz\+
URL url = new URL(sURL); /X; [ 9&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `ZC_F! E
httpConnection.setRequestProperty("User-Agent","NetFox"); {f<2VeJ
String sProperty = "bytes="+nStartPos+"-"; Fe{lM' 8
httpConnection.setRequestProperty("RANGE",sProperty); dXg.[|S*
Utility.log(sProperty); Wz;7 |UC
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InputStream input = httpConnection.getInputStream(); p gWBW9\
//logResponseHead(httpConnection); &,JrhMr\
W0R<^5_
..)O/g.
byte[] b = new byte[1024]; aHuZzYQ*"j
int nRead; bXmX@A$#Io
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a=]tqV_
{ N7=lSBm
nStartPos += fileAccessI.write(b,0,nRead); w|lA%H7`J
//if(nThreadID == 1) 4$~eG"wu
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {mr!E
} Nb(c;|nV
j0_)DG
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Utility.log("Thread " + nThreadID + " is over!"); #{-B`FAQ
bDownOver = true; J!YB_6b
//nPos = fileAccessI.write (b,0,nRead); vz[oy|{F
} mu@He&w"
catch(Exception e){e.printStackTrace ();} suiO%H^t
} ] -iMo4H
} avxr|uk
FN0)DN2d}
waT'|9{
//打印回应的头信息 THEpW{.E
public void logResponseHead(HttpURLConnection con) ' d' Dlg
{ 0@7%
for(int i=1;;i++) }M7{~ov#s
{ vP;
String header=con.getHeaderFieldKey(i); A6eIf
if(header!=null) O*jTrZ(k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ( y0
Utility.log(header+" : "+con.getHeaderField(header)); rr~O6Db
else L6<.>\^Z"
break; }w&W\g+E$
} w=JO$7
} icS%])3LF
?V&#nA
s3<gq x-&r
public void splitterStop() W2yNwB+{
{ nM#/uuRl|
bStop = true; N(c`h
} @@uKOFA?
-j& A;G
.=G?Zd
} "}*5'e.*
u]0{#wu;g
]WFr5
/* Z#uxa
**FileAccess.java (r*"}"ZG
*//文件访问(定位，写) c6-~PKJL
package NetFox; 9 n0?0mk
import java.io.*; ?$$Xg3w_#
`s8*n(\h
C}jFR] x)
public class FileAccessI implements Serializable{ l;7T.2J'Z
qL2!\zt>g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <Fo~|Nh|
RandomAccessFile oSavedFile; 7up~8e$_
long nPos; T:/mk`>
H^sImIEUT
/dI8o
public FileAccessI() throws IOException qzk!'J3*r<
{ "~2SHM@q
this("",0); Y' FB {
} 80_}}op?8
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+,c]FAx4
public FileAccessI(String sName,long nPos) throws IOException MZd?cS
{ LS:^K
oSavedFile = new RandomAccessFile(sName,"rw"); 7H])2:)
this.nPos = nPos; u!CcTE*
oSavedFile.seek(nPos); ^tFlA)
} [b:0j-
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public synchronized int write(byte[] b,int nStart,int nLen) #IvHxSo&
{ 3-Bz5sj9
int n = -1; 0?,<7}"<X
try{ S\M+*:7
oSavedFile.write(b,nStart,nLen); 9ERyr1-u v
n = nLen; joA>-k04
} zFi)R }Ot
catch(IOException e) 4|/}~9/
{ 8hV>Q
e.printStackTrace (); xp*Wf#BF
} A1Es>NK[qW
XOL_vS24
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return n; U6?3 z
} `T,^os#6
.k -!/^
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} #;0F-pt
z!G?T(SpA
l@:&0id4I
/* ,K15KN.'
**SiteInfoBean.java RF[Uy?es
*/ s5\<D7
package NetFox; sK@]|9ciQ
dvcLZK
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public class SiteInfoBean { uCHM
:sX4hZK=G
9 lXnNK |]
private String sSiteURL; //Site's URL qTz5P
private String sFilePath; //Saved File's Path SFjRSMi
private String sFileName; //Saved File's Name f"-3'kqo
private int nSplitter; //Count of Splited Downloading File GJ\bZ"vDo
/$d#9Uv
Y)68
public SiteInfoBean() )YVs=0j
{//nSplitter的缺省值为5 $sFqMy
//default value of nSplitter is 5 R$x(3eyx
this("","","",5); (c S'Nm5
} p`Ok(C_
r ?<?0j
fQxlYD'peb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]tNB^
{ LfvNO/:,
sSiteURL= sURL; ,(B/R8ZF~
sFilePath = sPath; emHaZhh
sFileName = sName; p ~pl|
this.nSplitter = nSpiltter; e7yn"kd
/Yj; '\3
pS "A{k)i
} *SYuq)
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" 1h~P,
public String getSSiteURL() 5Mp$u756
{ 06 an(&a9
return sSiteURL; W[LQ$uj
} p^C$(}Yh
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public void setSSiteURL(String value) HggINMG
{ \0;EHB
sSiteURL = value; S;SI#Vg@
} !KtP> `8
/~{fPS
:j[=
public String getSFilePath() Bxf&gDwjgr
{ )0\D1IFJ
return sFilePath; "td ,YVK
} ]u\-_PP
K_Kz8qV.?
&x3R+(H {
public void setSFilePath(String value) 1QbD]"=n
{ })?KpYk
sFilePath = value; #[]B: n6
} ]4Q~x
# ';b>J
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public String getSFileName() 6u,w
{ cS>xT cj
return sFileName; c3)6{
} }-@h H(
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public void setSFileName(String value) R=C+]
{ "d*-k R
sFileName = value; =.IAd<C
} )%q )!x
7Q|v5@;pU
.X"\ Mg
public int getNSplitter() ^@$T>SB1
{ |H%,>r`9S
return nSplitter; VO<P9g$UD
} ~Efi|A/
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d z\yP v~
public void setNSplitter(int nCount) A/OGF>
{ ,o\~d?4
nSplitter = nCount; $*7AG
} ~,{nBp9*
} qdZo cTf'
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: n\D
/* #VuiY
**Utility.java m,SWG[~
*/ (wp?tMN5#
package NetFox; bKQ-PM&I/t
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w"!zLB&9[
public class Utility { mSp;(oQ
CMfR&G,)
}^PdW3O*m,
public Utility() 2*Mu"v,
{ e9eBD
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Y~ Nt9L
} @|}=W Q
Ns-3\~QSi
//线程睡眠 GTW5f
public static void sleep(int nSecond) lsOZ%p%fV
{ A"B[F#
try{ &z"yls
Thread.sleep(nSecond); gal.<SVW
} $u{ 8wF/)
catch(Exception e) ^S^7u
{ ?Q: KW
e.printStackTrace (); :2MHx}]il
} 1y.!x~Pi,
} y73@t$|
]ChN]>o
//日志 !}Ty"p`
public static void log(String sMsg) w]Ci%W(
{ Q".AmHn
System.err.println(sMsg); mTZgvPJ!
} +WSM<S2 U
#}zL?s^G
{pEbi)CF,}
public static void log(int sMsg) J,^eq@(
{ / Hexv#3
System.err.println(sMsg); u )KtvC!
} |79n 1;+\?
} k&3'[&$I*,
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/* oW8 hC
**TestMethod.java 9h'klaE(
*/ fu7J{-<<R
package NetFox; 0V?:5r<
-_~T;cj6
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public class TestMethod { #'Lt_Yf!
=]F15:%Zq
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public TestMethod() .p(~/MnO
{ ///xx/weblogic60b2_win.exe =j!Ruy1
try{ .{LJ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LxxFosi8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j!QP>AM|`
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ov9kD0S
fileFetch.start(); Zkn1@a
} >-YWq
catch(Exception e){e.printStackTrace ();} ,a?$F1Z-
"e~"-B7(\Y
ZYD3[" ~x
} OcGHMGdn
9oJ=:E~CP
U/bQ(,3}
public static void main(String[] args) _sp/RU,J-3
{ s1NRUV2E
new TestMethod(); :1\QM'O
} ;&G8e*bM2
} +BE_K_56
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