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)); RKu'WD?sdH
} 2sj[hI
for(int i=0;i<nEndPos.length-1;i++) ^t&S?_DSZ
{ Q ke8BRBn
nEndPos = nStartPos[i+1]; Bb5|+bP
} i`3h\ku
nEndPos[nEndPos.length-1] = nFileLength; -a``
} poZ04Uxo>
} WoVPp*zlX
M ABrf`<b
eI8rnp(Ia
//启动子线程 cFcn61x-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {sn RS)-
for(int i=0;i<nStartPos.length;i++) f}JiYZ
{ ke'aSD
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i6L>,^Dg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M#BM`2!s
nStartPos,nEndPos,i); b&AGVWhh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RRW/.y
fileSplitterFetch.start(); <L4.*
} ^I=W<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;D}8acQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {MP8B'r-6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", < Y5pAStg
nEndPos = " + nFileLength); ^}JGWGib=+
// fileSplitterFetch[nPos.length-1].start(); "gD]K=
v6Vieo=
~HWH2g
//等待子线程结束 dNH6%1(s]0
//int count = 0; VRuY8<E
//是否结束while循环 bC_qoI<
boolean breakWhile = false; O$F<x,
mlq+Z#9
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while(!bStop) h(q,-')l_
{ ]mDsd*1
write_nPos(); [BPK0
Utility.sleep(500); (x;Uy
breakWhile = true; :@mBSE/
-~ w5yd
_Xs(3V@'}
for(int i=0;i<nStartPos.length;i++) Q"o* \I
{ ,"MRA
if(!fileSplitterFetch.bDownOver) |;~kHc$W
{ <SK%W=
breakWhile = false; IUB#Vdx
break; vD,ZEKAN
} I4[sf
} /y8=r"'G
if(breakWhile) C[E[|s*l
break; :%_*C09
>K|<hzZ
:Ma=P\J W
//count++; ORVFp]gG
//if(count>4) Ll" Kxg
// siteStop(); >XTDN
} $KSdNFtM)A
GyirE`
uu5AW=j
System.err.println("文件下载结束！"); )4nf={iM
} 9%{V?r]k
catch(Exception e){e.printStackTrace ();} %y7&~me
} 1L~y!il
U*P&O+(1'
(8JL/S;Z$
//获得文件长度 Lek!5Ug
public long getFileSize() jXa;ovPK
{ {..6{~L
int nFileLength = -1; ivgV5)".
try{ w'[^RZW:j
URL url = new URL(siteInfoBean.getSSiteURL()); C?xah?Sk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +c7e[hz
httpConnection.setRequestProperty("User-Agent","NetFox"); tu4-##{
_wp>AJ r
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int responseCode=httpConnection.getResponseCode(); [-ONs
if(responseCode>=400) 2p^Jqp`$
{ 6]%SSq&
processErrorCode(responseCode); ,,FO6+4f
return -2; //-2 represent access is error n(}cK@
} %-lilo
bD2):U*Fzo
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String sHeader; 8fI]QW
!^[i"F:G
AVn?86ri
for(int i=1;;i++) $Ph T:
{ teQ<v[W.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OON]E3yy
//Utility.log(in.readLine()); *KMW6dg;
sHeader=httpConnection.getHeaderFieldKey(i); Gy]ZYo(
if(sHeader!=null) QL].)Vgf
{ n]3Lqe;
if(sHeader.equals("Content-Length")) Ihn#GzM?u
{ DB=^Z%%Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); buj*L&
break; iBqxz:PHN(
} )ajF ca@v
} =<BPoGs5
else bZ5cKQ\6
break; $D][_I
} YcRo>:I
} T^Lg+g+I
catch(IOException e){e.printStackTrace ();} OMY^'g%w
catch(Exception e){e.printStackTrace ();} F `4a0~?
8wf[*6VwV
p2=+cS"HC
Utility.log(nFileLength); >s%&t[r6
fb=[gK#*,
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return nFileLength; v1R t$[
} hZwbYvu
(drDC1\
^~7/hm:
//保存下载信息（文件指针位置） s7Z+--I)L
private void write_nPos() CMiE$yC
{ G m~2s;/
try{ x:? EL)(
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,hVDGif
output.writeInt(nStartPos.length); Y00hc8<
for(int i=0;i<nStartPos.length;i++) Hob n{E
{ 4!U)a
// output.writeLong(nPos); lf9mdbm
output.writeLong(fileSplitterFetch.nStartPos); }m -A #4.
output.writeLong(fileSplitterFetch.nEndPos); ?*/1J~<(@
} 9F"^MzZ
output.close(); my}l?S[2d@
} t_"]n*zk1
catch(IOException e){e.printStackTrace ();} L; o$vI~U,
catch(Exception e){e.printStackTrace ();} r.ib"W#4
} )JXlPU
@Rw]boC
=K;M\_k%y
//读取保存的下载信息（文件指针位置） VBN=xg}
private void read_nPos() 8-s7s!j
{ =M."^X
try{ DX(!G a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8dUP_t~d#q
int nCount = input.readInt(); OnND(YiX
nStartPos = new long[nCount]; 4XNdsb
nEndPos = new long[nCount]; CQns:.`$`
for(int i=0;i<nStartPos.length;i++) `gX$N1(
{ `L m9!?
nStartPos = input.readLong(); MC~<jJ,
nEndPos = input.readLong(); \"|7o8
} vUR@P -
input.close(); wv.HPmq
} TMG|"|
catch(IOException e){e.printStackTrace ();} (&!x2M
catch(Exception e){e.printStackTrace ();} (7A-cC
} d",VOhW7)S
O gtrp)x9
>|rU*+I`
private void processErrorCode(int nErrorCode) l_i&8*=Px
{ *cy!PF&
System.err.println("Error Code : " + nErrorCode); 1a tQ9
} r E&}B5PN=
2o<aEn&7|e
W}P9I&3
//停止文件下载 'pHxO,vo
public void siteStop() y4N2gBTKu
{ oqa8v6yG'
bStop = true; NI85|*h
for(int i=0;i<nStartPos.length;i++) #:xv]qb`k
fileSplitterFetch.splitterStop(); b#W(&b^q
YZZog6%
/wPW2<|"X.
} eZ|_wB'r
} lQqP4-E?
//负责部分文件的抓取 c+ukVn`r
**FileSplitterFetch.java Y(;u)uN_
*/ E[Bj+mX9
package NetFox; V$g!#V
34I;DUdcE
Vtv1{/@+c
import java.io.*; OjurfVw
import java.net.*; jk{m8YP)E
i$6o>V6
PM3fJhx
public class FileSplitterFetch extends Thread { o]aMhSol
]2rCn};
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String sURL; //File URL ,*Z/3at}5M
long nStartPos; //File Snippet Start Position d Z}|G-:
long nEndPos; //File Snippet End Position hg-M>|s7
int nThreadID; //Thread's ID >rY^Un{Z
boolean bDownOver = false; //Downing is over 3 p!t_y|SX
boolean bStop = false; //Stop identical l}~9xa}:D|
FileAccessI fileAccessI = null; //File Access interface 42=/$V
c!a1@G
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException fF^A9{{BS
{ %+oV-o\ #A
this.sURL = sURL; ;umbld0
this.nStartPos = nStart; 9)$gD
this.nEndPos = nEnd; H`nd |
nThreadID = id; h|.{dv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !X\aZ{}Q
} kd OIL2T
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&#;lmYyaui
public void run() wPvYnhr|G-
{ +&[X7r<
while(nStartPos < nEndPos && !bStop) `8kL=%(h
{ B:6VD /qC
0,wmEV!)
XnB-1{a1
try{ %FJB9?9=|
URL url = new URL(sURL); I+rLKGZC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fv:&?gc
httpConnection.setRequestProperty("User-Agent","NetFox"); h]WW?.
String sProperty = "bytes="+nStartPos+"-"; ,p V3O`z
httpConnection.setRequestProperty("RANGE",sProperty); Je~`{n
Utility.log(sProperty); p/gf
w01u~"E
(^$SMuC
InputStream input = httpConnection.getInputStream(); @@& ?,3
//logResponseHead(httpConnection); {-51rAyi
>2mV{i&
fJ;1ii~
byte[] b = new byte[1024]; pg3h>)$/
int nRead; \9 k3;zw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hlz$@[$
{ WfYC`e7q
nStartPos += fileAccessI.write(b,0,nRead); z q@"qnr
//if(nThreadID == 1) 9`Xr7gmQf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DI=?{A
} .50ql[En
AtP!.p"j
ivvm.7{
Utility.log("Thread " + nThreadID + " is over!"); lL*"N|Y
bDownOver = true; v\R-G
//nPos = fileAccessI.write (b,0,nRead); f`-UC_(;
} |3Bmsd/3
catch(Exception e){e.printStackTrace ();} Asli<L(?`
} ldr~=<hsZ
} T&->xef=
"]B%V!@
Hli22~7T:
//打印回应的头信息 V"8w:?
public void logResponseHead(HttpURLConnection con) LUEZqIf
{ ddw^oU
for(int i=1;;i++) !BN@cc[%
{ J#?z/3v(
String header=con.getHeaderFieldKey(i); 8b< 'jft
if(header!=null) } ^WmCX2a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j"n"=rTTQ
Utility.log(header+" : "+con.getHeaderField(header)); {Z#=ppvs
else $j"BHpN
break; c>BDw<
} 0?=a$0_C
} >~})O&t
$t.M`:G
uYXkD#{
public void splitterStop() %jxeh.B3B
{ 5RR4jX]
bStop = true; ageTv/
} r tH #j
^AC2 zC
,YF1*69
} !_>o2
MGH2z:
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/* mj&$+zM>
**FileAccess.java 6!v$"u|[!'
*//文件访问(定位，写) TnJNs
package NetFox; WntolYd
import java.io.*; gq050Bl)
"8/BVW^bv
CwwZ~2
public class FileAccessI implements Serializable{ ["15~9
a6 w'.]m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9z7rv,
RandomAccessFile oSavedFile; HrHtA]
long nPos; b&*N
?4#wVzuzA
n= FOB0=
public FileAccessI() throws IOException !&R|P|7qN}
{ 6/&|)gW',
this("",0); 7myYs7N8[
} r+,JM L
t_id/
d?N[bA
public FileAccessI(String sName,long nPos) throws IOException MC%!>,tC
{ *`V r P
oSavedFile = new RandomAccessFile(sName,"rw"); R[}fr36>/
this.nPos = nPos; E6fs&
oSavedFile.seek(nPos); $j/#IzD1D
} ]BfJ~+ N
b 4A1M
=jvL2ps<
public synchronized int write(byte[] b,int nStart,int nLen) `Af5%m[
{ X08[,P#I
int n = -1; dlBr2 9
try{ N[kl3h%q
oSavedFile.write(b,nStart,nLen); lCGEd 3
n = nLen; %:\GYs(Y
} A}_0iwG
catch(IOException e) synueg
{ 7towjwr
e.printStackTrace (); d^I:{Ii'
} a"phwCc"%
0](V@F"~
3z -="_p
return n; Xr{ r&Rl
} %XH%.Ps/
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G!7A]s>C
} =1zRm >m
Q; BD|95nl
#2;8/"v
/* D;6C2>U~L
**SiteInfoBean.java ](>YjE0
*/ gQuU_dbXSB
package NetFox; (8Te{Kh'
zin'&G>l
lKV7IoJ&;
public class SiteInfoBean { S%o6cl=
3 ]w a8|
kg^5D3!2{Q
private String sSiteURL; //Site's URL iwI}
private String sFilePath; //Saved File's Path 3W}qNY;J
private String sFileName; //Saved File's Name BKQwF*<V
private int nSplitter; //Count of Splited Downloading File lhB;jE
+ De-U.
1l\.>H\E
public SiteInfoBean() TmEh$M
{//nSplitter的缺省值为5 60r0O5=|Fl
//default value of nSplitter is 5 `Db%:l^e
this("","","",5); 8" (j_~;
} dm"|\7
}UqL2KXi4
ja^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j){0>O.V
{ ?6 "B4%7b
sSiteURL= sURL; J/\^3rCB
sFilePath = sPath; ,AG k4]
sFileName = sName; T 2Gscey
this.nSplitter = nSpiltter; pXK-,7-
(} Y|^uM,
,<U
} ;9hS_%ldX4
*ch7z|wo.
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public String getSSiteURL() fT5vO.a
{ .cs4AWml<
return sSiteURL; u\u6<[>P
} #ib?6=sPC
oPrK{flm
D9\ EkX
public void setSSiteURL(String value) a~F\2`Q
{ K'b #}N\
sSiteURL = value; wQ '_, d
} E|x t\*
%APeQy"6#^
v[<;z(7Qk
public String getSFilePath() E<77Tj
{ ;:8SN&).
return sFilePath; 8!qzG4F/
} \8/$ZEom
D}nIF7r2N
X"S")BQ q
public void setSFilePath(String value) #%.fsJNA$
{ 4td9=dNA+l
sFilePath = value; jB3Rue:+g
} y@Ak_]{b
"2hs=^&8
Y >U_l:_^
public String getSFileName() /v7o!D1G
{ CB>*(Mu
return sFileName; P5`BrY,hZ
} 2I0Zr;\f
=S|dzgS/
|[MtUWEW
public void setSFileName(String value) Sw~L M&A
{ /N=M9i\;
sFileName = value; MmD1@fW32#
} rl:D>t(:.
eI=:z/pd
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public int getNSplitter() \ 6 :7
{ JO&+W^$uY}
return nSplitter; ;f9a0Vs
} $mut v=IO
#~`d ;MC
rWN%Tai-
public void setNSplitter(int nCount) }PxPJ$o
{ HD;l1W)
nSplitter = nCount; %VwkYAgA
} 6:AZZF1
} @P6*4W
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]I(<hDuRp
/* aU%QJ#j
**Utility.java ,`ju(ac!
*/ `0Xs!f
package NetFox; |^ J5YwCf
P/T`q:<H
3/EJ^C
public class Utility { J6g:.jsK!
\OK"r-IO
DcmRvi)&6
public Utility() )X'ln
{ <E\vc6n
jDCf]NvOPM
G!g];7PG(
} ,*g.?q@W2
{{ +8oRzY
//线程睡眠 #EIcP=1m4
public static void sleep(int nSecond) fU^5Dl
{ zI.:1(,
try{ =iE)vY,?"}
Thread.sleep(nSecond); Gw?ueui<
} -[xbGSj{
catch(Exception e) /gq\.+'{
{ /H :Bu
e.printStackTrace (); |!uC [=
} 2R~[B]2"r
} (n4Uc308
&f<Ltdw
//日志 &-p!Lg&D
public static void log(String sMsg) `l+9g"q
{ |]tsf /SA
System.err.println(sMsg); z9ZS&=>
} t9[%o=N~lD
lCJ/@)
vfOG(EkG.?
public static void log(int sMsg) N3@gvS
{ i?|b:lcV
System.err.println(sMsg); G'WbXX
} AJ)N?s-=
} Zr$D\(hX
06>+loBG
PvVn}i
/* XseP[
**TestMethod.java [A#>G4a<
*/ !&5B&w{u~!
package NetFox; %p tw=Ju
:0(:}V3z\
CC XOxd
public class TestMethod { >^Y)@J
s Vg89I&
SaiYdJ
public TestMethod() s^ K:cz
{ ///xx/weblogic60b2_win.exe J9XV:)Yv#
try{ >(eR0.x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o`7B@]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2[5z6oG
SiteFileFetch fileFetch = new SiteFileFetch(bean); trM)&aQto
fileFetch.start(); }Fb966 $
} }!@X(S!do
catch(Exception e){e.printStackTrace ();} i2n66d
jn#Ok@tZ
~0Xx]
} 5g4xhYl70n
#4ii!ev
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public static void main(String[] args) A?Gk8
{ `&>CK`%Xu
new TestMethod(); 6Y/TqI[
} 8M7pc{
} J]qx4c
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