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)); jq+:&8!8(e
} Z DnAzAR
for(int i=0;i<nEndPos.length-1;i++) -V}ZbXJD
{ &fifOF#[e
nEndPos = nStartPos[i+1]; \LDcIK=
} Wu693<
nEndPos[nEndPos.length-1] = nFileLength; (9!kKMQW'
} :$oiP
} 15!b]':
`wNJ*`
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//启动子线程 A Zv| |8p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~;nW+S$o
for(int i=0;i<nStartPos.length;i++) [,mcvO;
{ 9S)A6]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :']O4v#^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S3YAc4
nStartPos,nEndPos,i); "QV1G'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SrXuiiK
fileSplitterFetch.start(); r A9Rz^;xa
} 9!Vp-bo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `O}bPwa{>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); '8fh(`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'a enhj
nEndPos = " + nFileLength); hFt~7R
// fileSplitterFetch[nPos.length-1].start(); 2pAshw1G
x`p3I*_HT5
.y~~[QF}8
//等待子线程结束 X]t *
//int count = 0; )jN fQ!?/
//是否结束while循环 SP5t=#M6
boolean breakWhile = false; u5dyhx7
o`[X _
?a-}1A{
while(!bStop) XBHv V05mv
{ }i2dXC/
write_nPos(); WFpR@53Db
Utility.sleep(500); s&qr2'F+z
breakWhile = true; &bS!>_9
n0ls a@l
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for(int i=0;i<nStartPos.length;i++) r#K"d
{ 58_aI?~>>
if(!fileSplitterFetch.bDownOver) {,i='!WIm
{ 2v\-xg%1
breakWhile = false; .@]M'S^1
break; ^b(>Bg)T
} =DXvt5G
} IctLhYZ
if(breakWhile) dLTA21b#
break; \)9R1zp/x
>.#tNFAs
E{6X-C[)v
//count++; =u]FKY
//if(count>4) Nh\y@\F>
// siteStop(); t8FgQ)tk
} =;A~$[g
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System.err.println("文件下载结束！"); wenJ(0L|
} %uhhQ<zs%
catch(Exception e){e.printStackTrace ();} RlTVx:
} We*c_;@<
Q Ph6 p3bg
zs@[!?A,
//获得文件长度 d@t3C8
public long getFileSize() yj{:%Km:`
{ j\8'P9~%
int nFileLength = -1; -2Azpeh
try{ uDi#a~m@
URL url = new URL(siteInfoBean.getSSiteURL()); %uLyL4*L(p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9CTvG zkw
httpConnection.setRequestProperty("User-Agent","NetFox"); A)q,VSR8
4lfJc9J
"t"&6\
int responseCode=httpConnection.getResponseCode(); >zAI#N4
if(responseCode>=400) H@WQO]PA
{ QabYkL5@
processErrorCode(responseCode); [M6/?4\
return -2; //-2 represent access is error r#[YBaCZJ
} OHha5n
0,`$KbV\
E={W^k!Vz:
String sHeader; :WBl0`kW]4
f*SAbDE
>K;'dB/m;1
for(int i=1;;i++) MhpR^VM'.
{ .U !;fJ9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3 e9fziQ~
//Utility.log(in.readLine()); SbW6O_
sHeader=httpConnection.getHeaderFieldKey(i); ba
if(sHeader!=null) O(E-ox~q
{ &Wup 7
if(sHeader.equals("Content-Length")) ZVek`Cc2
{ (_lc< Bj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'u2Qq"d+
break; AFSFXPl "
} ?k:i3$
} S[ ,r.+
else h&6x.ps@
break; lEC58`Ws
} ai,Mez
} ]jzINaMav
catch(IOException e){e.printStackTrace ();} =JnUTc_u
catch(Exception e){e.printStackTrace ();} ico(4KSk
c!%:f^7g
'HV}Tr
Utility.log(nFileLength); o*u A+7n
,uP1U@Cas
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return nFileLength; G#4cWn'
} %j=,c{`Q
7>m#Y'ppl@
+6{KrREX)
//保存下载信息（文件指针位置） ngJES`0d
private void write_nPos() VRoeq {
{ G#! j`
try{ (Rk g
output = new DataOutputStream(new FileOutputStream(tmpFile)); w`Dzk.2
output.writeInt(nStartPos.length); EF{_-FXY
for(int i=0;i<nStartPos.length;i++) &~Q ?k
{ JPk3T.qp
// output.writeLong(nPos); Q=9S?p M
output.writeLong(fileSplitterFetch.nStartPos); .0q %A1H
output.writeLong(fileSplitterFetch.nEndPos); y*6r&989
} :LFwJ
output.close(); yXw xq(32
} BI=Ie?
catch(IOException e){e.printStackTrace ();} g5to0
catch(Exception e){e.printStackTrace ();} \?fl%r2
} EQ>bwEG
.-N9\GlJ,d
*#;rp~
//读取保存的下载信息（文件指针位置） um&e.V)N
private void read_nPos() +-#| M|a
{ E4[\lX$J
try{ 9=I(AYG{m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6#5@d^a
int nCount = input.readInt(); !{SU G+.2
nStartPos = new long[nCount]; @11voD
nEndPos = new long[nCount]; ?kb\%pcK
for(int i=0;i<nStartPos.length;i++) r/L3j0
{ DRVvW6s
nStartPos = input.readLong(); (.!q~G
nEndPos = input.readLong(); N1(}3O
} SJ7>*Sa(u$
input.close(); Z-H Kdv!d
} u6jJf@!ws
catch(IOException e){e.printStackTrace ();} (s{%XB:K
catch(Exception e){e.printStackTrace ();} s:cS 9A8
} 0tB9X9:,
sa+:c{
rsP-?oD8)
private void processErrorCode(int nErrorCode) $b$r,mc
{ yZFvpw|g
System.err.println("Error Code : " + nErrorCode); 6M$.gX G.
} Qq]UEI `Go
bTHa;* `
^ I,1kl~i
//停止文件下载 xyz-T1ib
public void siteStop() EGGy0ly
{ XW]|Mv[M
bStop = true; 1xq1te)
for(int i=0;i<nStartPos.length;i++) Yjk A^e
fileSplitterFetch.splitterStop(); }.zgVLL
~rY<y%K
wQnr*kyza
} 7qXgHrr0|U
} &"C1XM
//负责部分文件的抓取 W.:kE|a.g
**FileSplitterFetch.java %v~j10e
*/ ZVIBmx
package NetFox; iJrscy-
o ohf))
+bf%]
import java.io.*; 6x/ X8zu
import java.net.*; 6nGDoW#
E4y"$U%.
! 2Y, a
public class FileSplitterFetch extends Thread { |Be.r{l
-R7f/a8
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String sURL; //File URL [EGE|
long nStartPos; //File Snippet Start Position $X*$,CCIB
long nEndPos; //File Snippet End Position `O}. .N]g
int nThreadID; //Thread's ID <6L$:vT_
boolean bDownOver = false; //Downing is over gi;V~>kh
boolean bStop = false; //Stop identical 6u:5]e8
FileAccessI fileAccessI = null; //File Access interface `&9#!T.
<"[}8
Dh +^;dQ6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nVyb B~.=
{ 9'5,V{pj
this.sURL = sURL; RXx +rdF0
this.nStartPos = nStart; [>_(q|A6+
this.nEndPos = nEnd; W+K=M*^D;c
nThreadID = id; P<4jY?.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R?&S]?H
} #{ Uk4
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public void run() =h_4TpDQ
{ ^*{xTB57
while(nStartPos < nEndPos && !bStop) @#Xzk?+
{ 3UN Jj&-`
!&'xkw`
b$Uwj<v
try{ %W&=]&L
URL url = new URL(sURL); F~l3?3ZV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?ST}0F00}
httpConnection.setRequestProperty("User-Agent","NetFox"); Yaa M-o
String sProperty = "bytes="+nStartPos+"-"; q75F^AvH
httpConnection.setRequestProperty("RANGE",sProperty); 1@nR.v"$
Utility.log(sProperty); p6HZ2Q:a
RXWjFv~/
e&0B4wVAQ
InputStream input = httpConnection.getInputStream(); `chf8
//logResponseHead(httpConnection); y6PAXvv'{
3.dUMJ$_
jZ{S{"j
byte[] b = new byte[1024]; HK[sHB&
int nRead; aF;&#TsB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,<vrDHR
{ "]NQTUb;
nStartPos += fileAccessI.write(b,0,nRead); $Jr`4s
//if(nThreadID == 1) nO|S+S_9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zA"D0fr
} Q^p@ 1I
+tV(8h4
*UyV@
Utility.log("Thread " + nThreadID + " is over!"); TM^1{0;r5
bDownOver = true; /t9w%Y
//nPos = fileAccessI.write (b,0,nRead); q/B+F%QiMQ
} ASYUKh,h
catch(Exception e){e.printStackTrace ();} vSnb>z1
} %cm5Z^B1"
} a<Ns C1
FQ-(#[
Maa.>2v<
//打印回应的头信息 rL,)Tc|"
public void logResponseHead(HttpURLConnection con) YwF6/JA0^
{ =6W:O
for(int i=1;;i++) Zgg7pL)#c
{ @Op8^8$`
String header=con.getHeaderFieldKey(i); l =_@<p
if(header!=null) 0zTv'L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); <7jb4n<
Utility.log(header+" : "+con.getHeaderField(header)); yav)mO~QU6
else tm|lqa
break; T*{zL
} R/Y/#X^b
} tAC,'im:*
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rvmI 8
public void splitterStop() )-QNWN H
{ 18n84RkI9
bStop = true; `Eu(r]:W
} R Nv<kw
HJ'93,
bNaUzM!,H
} R_N<j
?}]kIK}MC
hL3,/^;E,
/* 5{u6qc4FW
**FileAccess.java G4{qWa/
*//文件访问(定位，写) ipzUF o<w
package NetFox; u:S@'z>
import java.io.*; &=?`;K
m+m6"yE#_
NSgHO`gU8
public class FileAccessI implements Serializable{ ( Lu.^
>C-_Zv<!T\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F889JSZ%
RandomAccessFile oSavedFile; wU ; f
long nPos; 1IlR
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public FileAccessI() throws IOException ZKR z=(
{ (wlsn6h
this("",0); wrO>#`Z
} rqFs[1wr>R
vl5n%m H>^
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public FileAccessI(String sName,long nPos) throws IOException Ad,r(0a LZ
{ qbEj\ b[
oSavedFile = new RandomAccessFile(sName,"rw"); 9V66~Bf5
this.nPos = nPos; Ds G *
oSavedFile.seek(nPos); `Of wl%G
} eTF8B<?
PD}R7[".>
rq1kj 8%2
public synchronized int write(byte[] b,int nStart,int nLen) %)/f; T6
{ *3/7wSV:
int n = -1; IP'igX
try{ @gqw]_W
oSavedFile.write(b,nStart,nLen); `es($7}P_W
n = nLen; @*DIB+K
} p-pw*wH0
catch(IOException e) (v`;ym
{ FR}H$R7#
e.printStackTrace (); .?p}:
} &1p8#i
+r0eTP=zf
4{DeF@@
return n; bS<@Rd{g
} Jrk^J6aa
}R1`ThTM
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} j>o +}p?3I
B (1,Rq[
_onp%*
/* p0rwiBC=q
**SiteInfoBean.java eCp|QSXE
*/ >$mSFJz5S
package NetFox; hf<$vRti>
UPKi/)C;
7rSUSra
public class SiteInfoBean { ^@Qi&g`lr?
lk +K+Ra/
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private String sSiteURL; //Site's URL ;1.>"zX(
private String sFilePath; //Saved File's Path mbBRuPEa=u
private String sFileName; //Saved File's Name R1.sq(z`
private int nSplitter; //Count of Splited Downloading File &#@>(u:.
i$ L]X[
eUkoVr
public SiteInfoBean() j/9QV
{//nSplitter的缺省值为5 KupMndK
//default value of nSplitter is 5 CjQ"oQw
this("","","",5); 5FSv"=
} , Ln
u-[t~-(a
T'M66kg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q==v!"Gi|
{ jAK{<7v4U
sSiteURL= sURL; #tZf>zrs
sFilePath = sPath; AD@PNM
sFileName = sName; u7"VeTz
this.nSplitter = nSpiltter; Tj=dL
_GO+fB/Q1
HqdJdWl#"
} {(OIu]:
e5ru:#P.p
*>'2$me=
public String getSSiteURL() h)_Gxe"x
{ sJb)HQ,7x
return sSiteURL; DAnb.0
} [tqO}D
jRG\C=&(x
kz0=GKic
public void setSSiteURL(String value) 2Nn1-wdhb
{ n`)7Y`hBhP
sSiteURL = value; .H^P2tp
} 'yd@GQM&
90T%T2K
-2&i)S0R
public String getSFilePath() mhk/>+hF
{ 3fxNV<
return sFilePath; _E6}XNS
} o}=.
ufCqvv>'
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public void setSFilePath(String value) Mjj}E >&
{ y-#
sFilePath = value; "XNu-_$N<a
} =#(0)p$EC
i7nL_N
h `ME(U~<<
public String getSFileName() :,kU#eZ$-
{ Vf0fT?/K
return sFileName; n}A?jOSAe
} xHB/]Vd-
o-~~,n\
nMGrG
public void setSFileName(String value) |rFR8srPG
{ -2\ZzK0tM
sFileName = value; /zG+]
} gcg>Gjp
i_u {5 U;
2L2 VVO
public int getNSplitter() 1n'$Ji7
{ YOV :
return nSplitter; 5g``30:o
} WRD A `
2@ 9pr
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public void setNSplitter(int nCount) MBB5wj
{ r219M)D?
nSplitter = nCount; 9g Bjxqm
} 3;a R\:p@w
} ,?g=U8y|
sEce{"VC
^/>Wr'w
/* 4\N_ G @
**Utility.java J/'M N
*/ wE$s'e
package NetFox; 5"JU?e59M
F7{R~mS;
c>ad0xce6
public class Utility { 1")FWN_K/T
p9-0?(]
lC#RNjDp/~
public Utility() G02ox5X
{ !4R>O6k
74K)aA
TbLe6x
} vv+D*e&<
*hVb5CS
//线程睡眠 BeK2;[5C
public static void sleep(int nSecond) Ge~q3"
{ <EMkD1e
try{ =m}TU)4.
Thread.sleep(nSecond); ^m*3&x8
} E4+b-?PB~
catch(Exception e) $$JIBf8
{ ~TDzq -U)
e.printStackTrace (); 4`nqAX~'f
} ?6i;)eIOI
} L=,OZ9aA
}YQ:6I
//日志 &=6%>
public static void log(String sMsg) <cYp~e%xIw
{ &hayR_F9
System.err.println(sMsg); cd!|Ne>fe
} W57&\PXYn
kMy<G8 s
2H[ ; v+
public static void log(int sMsg) 0p-#f|ET
{ FV A UR
System.err.println(sMsg); _J,xT
} flG=9~qcGQ
} t5paYw-b
R"*R99
:BZMnCfA
/* R2w`Y5#`
**TestMethod.java &5u BNpH
*/ Y0@yD#,0~
package NetFox; *Bs^NU.
ic-IN~J-
ASW4,%cl
public class TestMethod { ivfXat-
#{x5L^v>]
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public TestMethod() H"+wsM^@
{ ///xx/weblogic60b2_win.exe exQ#<x*
try{ &]< 3~6n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 66Gx.tE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (SF1y/g@=
SiteFileFetch fileFetch = new SiteFileFetch(bean); Z:@6Lv?CN
fileFetch.start(); _gW{gLYyJ
} )lh8 k{
catch(Exception e){e.printStackTrace ();} &~#iIk~%
DLi?'K3t
XJSa]P^B1
} R&#tSL
7^MX l
d+6]u_J
public static void main(String[] args) ;i\C]*
{ F$Q04Qw
new TestMethod(); RN[]Jt#6
} <Ct_d Cc
} (#o t^
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