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)); v%6mH6V
} :n t\uwh
for(int i=0;i<nEndPos.length-1;i++) g9$P J:
{ hy?e?^
nEndPos = nStartPos[i+1]; kbF+aS
} NDv_@V(D
nEndPos[nEndPos.length-1] = nFileLength; lq%6~va
} gvx {;e
} GE0,d
etHkyF
A_vf3 *q
//启动子线程 NtnKS@Ht
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; IhYTK%^96
for(int i=0;i<nStartPos.length;i++) oA1d8*i^E
{ 6%&RDrn
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U;Ne"Jh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q:4euhz*
nStartPos,nEndPos,i); qr~=S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $sX X6K),
fileSplitterFetch.start(); 82bOiN15
} `mfN3Q*[c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %G%D[ i]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $_P*Bk)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pd1V8PZSG
nEndPos = " + nFileLength); #g6*s+Gm
// fileSplitterFetch[nPos.length-1].start(); VP<_~OLc
}N6r/ VtOQ
d^Jf(NE0Yo
//等待子线程结束 4}\Dr %US
//int count = 0; ,n&e,I
//是否结束while循环 `?PpzDV7Y
boolean breakWhile = false; %bs~%6)
gqi|k6V/
MSMgaw?
while(!bStop) [sT}hYh+
{ -#ta/*TT:
write_nPos(); 8eVQnp*
Utility.sleep(500); HAi'0%"
breakWhile = true; C"We>!
Ehv*E
'n)]"G|
for(int i=0;i<nStartPos.length;i++) %O< qw
{ [H!8m7i;
if(!fileSplitterFetch.bDownOver) zU7/P|Dw+
{ b2Jgg&?G
breakWhile = false; z^q ~|7
break; ]5=C3Y
} #el i_Cxe
} -brn&1oJ
if(breakWhile) F9SkEf]99
break; mJ3|UClPS
xqua>!mqS
{{\ d5CkX
//count++; pM^r8kIH
//if(count>4) zeZ}P>C
// siteStop(); r^$4]@Wn
} dIUg e`O9
k7\h- yn{
:&/b}b!)AX
System.err.println("文件下载结束！"); * @QC:1k
} /4R|QD
catch(Exception e){e.printStackTrace ();} ?5>Ep:{+/
} 'z=QV{ni
q i27:oJ
-Xw i}/OX
//获得文件长度 QE.a2 }
public long getFileSize() B-<H8[GkG1
{ PJCRvs|X
int nFileLength = -1; V_SZp8
try{ i8tH0w/(M
URL url = new URL(siteInfoBean.getSSiteURL()); K`25G_Y3@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `V;vvHP A
httpConnection.setRequestProperty("User-Agent","NetFox"); tw`{\kWG
A;4O,p@
^@&RJa-kb
int responseCode=httpConnection.getResponseCode(); km]RrjRp
if(responseCode>=400) %:P&!F\?
{ Xiyh3/%yy
processErrorCode(responseCode); TzCNY@y
return -2; //-2 represent access is error #Zm%U_$<
} $YmD;
.!\NM&E
`;@#yyj:_
String sHeader; )T=cd
Qo!/n`19
DKjkO5R\
for(int i=1;;i++) pm*6&,
{ bOi`JJ^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &s|&cT
//Utility.log(in.readLine()); g]=w_
sHeader=httpConnection.getHeaderFieldKey(i); 9Okb)K95
if(sHeader!=null) u_C/Y[ik
{ SLa\F
if(sHeader.equals("Content-Length")) ,~!rn}MI<
{ oM=Ltxv}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); xJvM l`2;
break; QT5,_+ho
} ?0Qm
} nJ.<yrzi
else %CxrXU
break; S}=euY'i
} .H,wdzg)
} `XwFH#_
catch(IOException e){e.printStackTrace ();} %lw!4Z\gg
catch(Exception e){e.printStackTrace ();} S z3@h"
FQbF)K~e
+$eEZ;4
Utility.log(nFileLength); Yxal%
xp395ub6
-`mHb
return nFileLength; 8?lp:kM
} UqaLTdYG
%n3lm(-0U
Lh%>> Ht{
//保存下载信息（文件指针位置） }*2q7K2bj
private void write_nPos() piRP2Lbm*
{ p&nIUx"
try{ CvwC| AW
output = new DataOutputStream(new FileOutputStream(tmpFile)); uZe|%xK$y
output.writeInt(nStartPos.length); yW&|ZJF?
for(int i=0;i<nStartPos.length;i++) A;t6duBDf/
{ Y5}<7s\UDO
// output.writeLong(nPos); ( aGwe@AS
output.writeLong(fileSplitterFetch.nStartPos); %|l^oC+E
output.writeLong(fileSplitterFetch.nEndPos); Zd/ACZ[
} ;NrN#<j(!
output.close(); 8+Y+\XZG
} .[v4'ww^
catch(IOException e){e.printStackTrace ();} ,8KD-"l^g
catch(Exception e){e.printStackTrace ();} 0L "+,
} PKoB~wLH
<z3:*=!
3[RbVT
//读取保存的下载信息（文件指针位置） 1D42+cy
private void read_nPos() }";\8
{ y/>]6Pj
try{ SArSi6vF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [@U2a$k+d
int nCount = input.readInt(); vHY."$|H
nStartPos = new long[nCount]; 6.z8!4fpl
nEndPos = new long[nCount]; e}u#:ysj
for(int i=0;i<nStartPos.length;i++) OPp>z0p%6X
{ zV(F9}^
nStartPos = input.readLong(); /dU-$}>ZI
nEndPos = input.readLong(); 69U[kW&
} qM(n]{H
input.close(); D8otUDB{
} C:77~f-+rQ
catch(IOException e){e.printStackTrace ();} 9/rX%
catch(Exception e){e.printStackTrace ();} $z-zscco
} #]ZOi`;
0hTv0#j#
O`nrXC{
private void processErrorCode(int nErrorCode) <lHelX=/
{ 6{rH|Z
System.err.println("Error Code : " + nErrorCode); nRpZ;X)'.
} ?@"B:#l
#GBe=tm\K
sK~d{)+T
//停止文件下载 &J~vXk: !
public void siteStop() YYrXLt:
{ t_@xzt10y
bStop = true; 'H0b1t1S%
for(int i=0;i<nStartPos.length;i++) 1LTl=tS#
fileSplitterFetch.splitterStop(); ;~Eb Q
J1I"H<}-6
8iTX}$t\{
} mOj6 4}_`"
} *@J
//负责部分文件的抓取 <(Ub(
**FileSplitterFetch.java =]h5RC
*/ }(AgXvRq
package NetFox; #un#~s 7Q
M6E.!Cs
@Oe!*|?mS
import java.io.*; #4. S2m4
import java.net.*; $O*rxQ}
2| u'J
(\ `knsE!
public class FileSplitterFetch extends Thread { dQ97O{O:i
!br0s(|
?MevPy`H
String sURL; //File URL &DdFK.lt
long nStartPos; //File Snippet Start Position |I7-7d-;/
long nEndPos; //File Snippet End Position .aWEXJ
int nThreadID; //Thread's ID :]%z8,6k
boolean bDownOver = false; //Downing is over IxwOzpr
boolean bStop = false; //Stop identical jq{rNxdGx
FileAccessI fileAccessI = null; //File Access interface ,^MA,"8
gd>Op
|r"1 &ow5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Sr)rKc
{ Ic4>kKh
this.sURL = sURL; Zfyr&]"
this.nStartPos = nStart; {s}@$rW
this.nEndPos = nEnd; wy5vn?T@
nThreadID = id; t.m65
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OHeVm-VC
} * iW>i^
zR2'xE*
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public void run() "(/ 1]EH`
{ (,eH*/~/
while(nStartPos < nEndPos && !bStop) mjbr}9
{ 2F(zHa
7Wg0-{yK4
(q+U5Ls6
try{ 0eY$K7 U
URL url = new URL(sURL); *V(TNLIh;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lJ!+n<K+
httpConnection.setRequestProperty("User-Agent","NetFox"); {uEu ^6a5
String sProperty = "bytes="+nStartPos+"-"; J2_DP
httpConnection.setRequestProperty("RANGE",sProperty); T_CYSS|fX
Utility.log(sProperty); s$e0;C!D
@)mH"u!(7
!n4p*<Y6
InputStream input = httpConnection.getInputStream(); kQXtO)
//logResponseHead(httpConnection); gio'_X
^YzFEu$
Wd'wL"6De
byte[] b = new byte[1024]; o >bf7+D
int nRead; Eh;SH^&6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !h&A^sAc
{ (v*$ExF
nStartPos += fileAccessI.write(b,0,nRead); 9,y*kC
//if(nThreadID == 1) #"%=7(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _A%} >:q
} R*I{?+
VJ P]Jy_
jJ-j
Utility.log("Thread " + nThreadID + " is over!"); z8+3/jLN0B
bDownOver = true; Z+ [Nco
//nPos = fileAccessI.write (b,0,nRead); (NUwkAOM}
} 'M2Jw8i
catch(Exception e){e.printStackTrace ();} UX=JWb_uGm
} 'S<ebwRd=
} 4`uI)N(}*
+hg|!SS@5
zRsG$)B
//打印回应的头信息 A<.`HCv2
public void logResponseHead(HttpURLConnection con) 0hK)/!Y
{ Gc}d#oo*k
for(int i=1;;i++) uNV(r"
{ pulE6T7x
String header=con.getHeaderFieldKey(i); CZg$I&x
if(header!=null) h0`@yo
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uZ*;%y nQ
Utility.log(header+" : "+con.getHeaderField(header)); niY9`8
else nb0V~W
break; qCOe,$\1/
} G@b|{!
} bWAhK@epI
knZee!FA7
g&;:[&%T]
public void splitterStop() "Q]`~u':
{ T:S+Pt~
bStop = true; 3=V79&
} RajzH2j+>
+K2jYgy
=p|,~q&i
} ?cf9q@eAH
75}BI&t3k
Yd:8iJA
/* fLl~a[(5
**FileAccess.java G (Fi
*//文件访问(定位，写) %c)^8k;I
package NetFox; k_.%(ZE
import java.io.*; " cx\P,<
QcG4~DEX4
Js[dT|>.
public class FileAccessI implements Serializable{ d(zBd=;
W#E-vi+l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 TG'_1m*$
RandomAccessFile oSavedFile; ^B~z .F i
long nPos; g|8G!7O
jV`xRjh
dM8`!~#&PI
public FileAccessI() throws IOException w$4fS
{ }7E2,A9_"
this("",0); GL'zs8AKf
} Qc-jOl
_] veTAV
U=MFNp+
public FileAccessI(String sName,long nPos) throws IOException Oe=7z'o
{ rI)op1K
oSavedFile = new RandomAccessFile(sName,"rw"); Hrm^@3
this.nPos = nPos; z/(^E8F
oSavedFile.seek(nPos); vL(7|K
} Gb.r!W8
Va>~7
_oxhS!.*
public synchronized int write(byte[] b,int nStart,int nLen) uFNVV;~RFI
{ gtWJR
int n = -1; X*6bsYbK-
try{ GV'Y'
oSavedFile.write(b,nStart,nLen); <eKF
n = nLen; F Cg{!h
} 9mfqr$3
catch(IOException e) E'zLgU)r`
{ rkh+$*t@i7
e.printStackTrace (); :hB/|H*=
} ~#+ Hhc(
JSCe86a7<E
^=@L(;Y
return n; M \rW
} Kf#9-.}?
:it52*3=
]P;Ng=a
} Uc]S7F#
X-O/&WRYQ
CEjMHP$=
/* &OD)e@Tc
**SiteInfoBean.java E!w%oTx{OR
*/ `''\FPhh
package NetFox; V(n7hpS
qB PUB(
=Is.T
public class SiteInfoBean { v:kTZB
"b5:6\
yUcWX bT@
private String sSiteURL; //Site's URL 8%v1[Wi
private String sFilePath; //Saved File's Path _Vr>/f
private String sFileName; //Saved File's Name &|'k)6Rx
private int nSplitter; //Count of Splited Downloading File |%.V{vgP7
.jW+\mIX
K9h{sC
public SiteInfoBean() IF-g%
{//nSplitter的缺省值为5 FYh+G-Y#
//default value of nSplitter is 5 udYk 6
this("","","",5); +Zgh[a
} 9M{z@H/
nw|ls2
[O92JT:li
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) | wuUH
{ eCHT)35u
sSiteURL= sURL; W,'30:#Fr7
sFilePath = sPath; H|&[,&M>
sFileName = sName; w3oh8NRs_
this.nSplitter = nSpiltter; z4 4(
k4Ed7T-
<RQ\nU
} `{BY {
= rDoXm
HAJK%zLc
public String getSSiteURL() CYD&#+o
{ 8wJfGY
return sSiteURL; ;G!JKg
} ]Q-*xho
CtiTXDc_
$<&N#
public void setSSiteURL(String value) <2Q+? L{
{ 1#BMc%
sSiteURL = value; >;I$&
} zyb>PEd.
GSck^o2{
^i>Tm9vM
public String getSFilePath() (Q~ p"Ch
{ 8{QN$Qkn
return sFilePath; |/rms`YQ
} )xKZ)SxV
}U-h^x'
Z_^i2eJYT
public void setSFilePath(String value) K]5@bm
{ ;la sk4|
sFilePath = value; Xtv^q>!
} M:&g5y&
RlJt+lnV
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public String getSFileName() $2lrP]`>j.
{ <7-Qn(m,
return sFileName; zF'LbQz0[
} Lh eOGM
DL$O274uZ
XNODDH
public void setSFileName(String value) `<}Q4p
{ dV_ClH &)
sFileName = value; ECq(i(
} _J' _9M?>
Vu6$84>-,
NrQGoAOw
public int getNSplitter() -2Bkun4Pt
{ #6w\r&R6
return nSplitter; %NH#8#';2
} O"%b@$p\L
3QNu7oo
|"t)#BUtL
public void setNSplitter(int nCount) 1>5l(zK!9
{ hsYS<]
nSplitter = nCount; U tb"6_
} L;jzDng<
} :x85:pa
,mkXUW
|%p;4b
/* l;+nL[%`
**Utility.java M1UabqQ
*/ b8Bf,&:ys
package NetFox; 9@'^}c#
(6b*JQ^^
uO=yQ&
public class Utility { hn-+]Y:
{, +,:w7
6MsVV_/
public Utility() 5W%^g_I
{ Yz"B
\PHbJN:BI
+MHsdeGU1W
} : T` Ni
/#WRd}IjK
//线程睡眠 a| w.G "W
public static void sleep(int nSecond) W8bh49
{ (T&rvE
try{ j` RuK
Thread.sleep(nSecond); F6g)2&e{/
} 8\V
catch(Exception e) S}mZU!
{ h!@t8R
e.printStackTrace (); 3 VNPdXsh
} ]' ck!eG
} S_ELZO#7
c)L1@qdZ
//日志 NOzAk%s3I
public static void log(String sMsg) ,tZJSfHB
{ kfb*|
System.err.println(sMsg); c%?31t
} 2=?:(e9
$9~6M*
H YA<
public static void log(int sMsg) _BC%98:WP
{ Ln&'5D#
System.err.println(sMsg); 0ZRIi70u
} *!mT#Vm^
} QB3vp4pBg@
7IEG%FY T
A(j9T,!
/* oR``Jiob|
**TestMethod.java _lK+/"-l
*/ H{tG:KH
package NetFox; Bsr;MVD
Npr<{}ZE
[m*E[0Hu
public class TestMethod { PM(M c]6
AbqeZn
^/"[jq3F
public TestMethod() QGC%, F"+
{ ///xx/weblogic60b2_win.exe Ne!0`^`~
try{ 6}q8%[l|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6jDHA3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PN(P$6
SiteFileFetch fileFetch = new SiteFileFetch(bean); )(4.7>
fileFetch.start(); E((U=P}+g
} goJK~d8M*
catch(Exception e){e.printStackTrace ();} Xc>M_%+R
VuU{7:
47/14rY 2
} +VE] .*T
{/u}
k Q Sx65
public static void main(String[] args) mi`jY0e2
{ `]T#uP<u
new TestMethod(); zyHHz\{
} vq?aFX9F
} P5$L(x%~
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