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)); YglmX"fLf
} k_nql8H
for(int i=0;i<nEndPos.length-1;i++) 9m~p0ILh
{ YGCL2Y
nEndPos = nStartPos[i+1]; {[?(9u7R
} ExL0?FemWV
nEndPos[nEndPos.length-1] = nFileLength; 3m!X/u
} mSh[}%swj
} PBTnIU
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x)O!["'"
//启动子线程 D7Q$R:6|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >jc [nk
for(int i=0;i<nStartPos.length;i++) ]K,Tnyp
{ z/@slT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Od,qbU4O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fSvM(3Y<Qh
nStartPos,nEndPos,i); _5Ct]vy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >V8-i`
fileSplitterFetch.start(); )cMh0SGcM1
} -**g~ty)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wf>R&o6tr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3K0A)W/YEs
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OU $#5
nEndPos = " + nFileLength); _H7x9 y=
// fileSplitterFetch[nPos.length-1].start(); |~mOfuQb
ra gXn
O`t&ldU
//等待子线程结束 fdi\hg^x
//int count = 0; p}pjfG
//是否结束while循环 eF-."1
boolean breakWhile = false; qHlQ+:n
.~~T\rmI
!Pfr,a
while(!bStop) 7CURhDdk
{ C{xaENp
write_nPos(); ^EQ<SCh
Utility.sleep(500); F8,RXlGfA[
breakWhile = true; ,G?WAOy,
lE(HFal0-(
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for(int i=0;i<nStartPos.length;i++) YWO)HsjP
{ bI9~jWgGp
if(!fileSplitterFetch.bDownOver) TpwkD_fg
{ Zaf:fsj>
breakWhile = false; jZkcBIK2
break; FxWSV|Z
} ?_9
} LxSpctiNx
if(breakWhile) !")tU+:
break; 6Vnsi%{
Q1I6$8:7
W/bQd)Jvk
//count++; J$w<$5UY
//if(count>4) C]`$AqKl
// siteStop(); qvKG-|j
} z3m85F%dR
:v&$o'Sak
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System.err.println("文件下载结束！"); u$Jz~:=,
} [ =9T*Sp
catch(Exception e){e.printStackTrace ();} #:U%mHT(_
} )e=D(qd
;rGwc$?|
WH@,kH@
//获得文件长度 Zbt.t]N
public long getFileSize() '9Xu p
{ Eib5
int nFileLength = -1; /cQueUME`
try{ _P 3G
URL url = new URL(siteInfoBean.getSSiteURL()); ND#Yenye
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i0kak`x0
httpConnection.setRequestProperty("User-Agent","NetFox"); }t=!(GOb}
}9#r0Vja
pis`$_kmwV
int responseCode=httpConnection.getResponseCode(); CMG&7(MR
if(responseCode>=400) }Gm>`cw-
{ g-</ua(j
processErrorCode(responseCode); DIfaVo/"
return -2; //-2 represent access is error JWhdMU
} :tB1D@Cb6
Val|n*%
:W.(S6O(
String sHeader; p\tm:QWD;
03qQ'pq
2M#Q.F
for(int i=1;;i++) Ls$D$/:q?
{ _~J {wM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "R1NG?;q
//Utility.log(in.readLine()); 0oZ= yh
sHeader=httpConnection.getHeaderFieldKey(i); O1U=X:Zl
if(sHeader!=null) oAJM]%g{
{ [")o.(
if(sHeader.equals("Content-Length")) M2>Vj/
{ +yH7v5W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,,&*:<Q
break; kYqU9cB~
} 6azGhxh
} 2Aazy'/
else $=8 NED5
break; p{Yv3dNl
} F^t DL:
} Vvn2 Ep
catch(IOException e){e.printStackTrace ();} HJLG=mU
catch(Exception e){e.printStackTrace ();} G )trG9 .a
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k"T}2 7
Utility.log(nFileLength); rJT^H5!o"
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:bu/^mW[
return nFileLength; 7uS~MW
} jrlVvzZ
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RK'\C\gMDu
//保存下载信息（文件指针位置） 9N%We|L,c
private void write_nPos() J6s`'gFns
{ qo90t{|c
try{ .9on@S
output = new DataOutputStream(new FileOutputStream(tmpFile)); z0p*Z&
output.writeInt(nStartPos.length); X<`
for(int i=0;i<nStartPos.length;i++) 6Z6'}BDP
{ x=hiQ>BIO0
// output.writeLong(nPos); pMx*F@&nU
output.writeLong(fileSplitterFetch.nStartPos); I {S;L
output.writeLong(fileSplitterFetch.nEndPos); b9KP( _
} HZzDVCU
output.close(); G_3O]BMKd)
} iZ3IdiZ
catch(IOException e){e.printStackTrace ();} +j`5F3@
catch(Exception e){e.printStackTrace ();} 3nIU1e
} uy[At+%zg
+eWQa`g
\=?a/
//读取保存的下载信息（文件指针位置） J{p1|+h%
private void read_nPos() 6y%qVx#!
{ l6T-}h:=
try{ pXT4)JDpc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^pAAzr"hv
int nCount = input.readInt(); E"\<s3
nStartPos = new long[nCount]; %Q__!D[
nEndPos = new long[nCount]; xjuN-
for(int i=0;i<nStartPos.length;i++) d6?j`~[7#-
{ c?f4Q,%|
nStartPos = input.readLong(); f}#~-.NGs
nEndPos = input.readLong(); c@!_/0
} $Uq|w[LA
input.close(); :t"^6xt
} G6q }o)[m)
catch(IOException e){e.printStackTrace ();} fnjPSts0
catch(Exception e){e.printStackTrace ();} F 5bj=mI
} F'={q{2wH
VuhGx:Xl
*KZYv=s,u
private void processErrorCode(int nErrorCode) ?yrX)3hyH
{ vsCCB}7\
System.err.println("Error Code : " + nErrorCode); qOIyub
} 1y4|{7bb
}WC[$Y_@
Uu10)/.LC
//停止文件下载 UAkT*'cB
public void siteStop() !=*g@mgF
{ r_)' Ps
bStop = true; GfxZ'VIn
for(int i=0;i<nStartPos.length;i++) *)$Uvw E
fileSplitterFetch.splitterStop(); APn|\
p,5i)nEFj
|sJ[0z
} qTRsZz@
} ,uSMQS-O'4
//负责部分文件的抓取 /kZebNf6H
**FileSplitterFetch.java `&r+F/Ap2
*/ LiC*@W
package NetFox; rT=rrvV3g
m4[;(1
g+8OekzB5
import java.io.*; -P(efYk
import java.net.*; (+w*[qHe
J|W<;
)nC]5MXU
public class FileSplitterFetch extends Thread { DTX0
m<<+
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String sURL; //File URL a(m2n.0'>
long nStartPos; //File Snippet Start Position 8 `v-<J
long nEndPos; //File Snippet End Position ]{;gw<T
int nThreadID; //Thread's ID KaLzg5is
boolean bDownOver = false; //Downing is over w1FcB$
boolean bStop = false; //Stop identical f%A;`4`q
FileAccessI fileAccessI = null; //File Access interface %e8@*~h@
E'f{i:O"~
y B81f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %HhBt5w
{ D5gFXEeh
this.sURL = sURL; /m!BY}4W
this.nStartPos = nStart; :;v~%e{k
this.nEndPos = nEnd; vRTkgH#4l
nThreadID = id; N_LM/of|D
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :^<3>zk
} bS{bkE>
c rQ8q;:
h<h%*av|
public void run() K$z2YJ%
{ 3RUy,s
while(nStartPos < nEndPos && !bStop) xW+6qtG`
{ kx8G
qRu~$K
2zX]\s?3
try{ Do9x XK
URL url = new URL(sURL); s `e{}\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M+oHtX$
httpConnection.setRequestProperty("User-Agent","NetFox"); ),_@WW;k
String sProperty = "bytes="+nStartPos+"-"; &L3M]
httpConnection.setRequestProperty("RANGE",sProperty); U%-A?5
Utility.log(sProperty); *nd!)t
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_OYasJUMG
InputStream input = httpConnection.getInputStream(); l#&8x
//logResponseHead(httpConnection); ^ G]J,+
-$\y_?}
}YQX~="
byte[] b = new byte[1024]; Xa[.3=bV?
int nRead; aI'&O^w+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >[)7U _|p
{ A]*}HZ,
nStartPos += fileAccessI.write(b,0,nRead); 9p85Pv [M=
//if(nThreadID == 1) )w em|:H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rDtY[
} =&6eM2>P
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Utility.log("Thread " + nThreadID + " is over!"); *9 {PEx
bDownOver = true; MyOd,vU
//nPos = fileAccessI.write (b,0,nRead); -au^;CM
} xl{=Y< ;
catch(Exception e){e.printStackTrace ();} 5#6|j?_a
} :x3QRF
} t}_r]E,{u
cx,+k]9D
39c2pV[
//打印回应的头信息 g_E$=j92v
public void logResponseHead(HttpURLConnection con) ?PLPf>e
{ . P viA
for(int i=1;;i++) I]|Pq
{ oE@a'*.\
String header=con.getHeaderFieldKey(i); ;T\%|O=Ke
if(header!=null) hXw]K"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AhN4mc@
Utility.log(header+" : "+con.getHeaderField(header)); _1X!EH"
else BX/8O<s0
break; 7jrt7[{
} `b&%Hm
} wKh4|Ka
N>uRf0E>
O *C;Vqt
public void splitterStop() goNG' o %|
{ E#34Wh2z
bStop = true; O;Rqv
} /A\8 mL8
810|Tj*U%
c?Y*Y
} AD>e?u
:]K4KFM
Z9E\,Ly
/* `%bypHeSp
**FileAccess.java !vi>U|rh
*//文件访问(定位，写) D_2:k'4
package NetFox; Q>qUk@
import java.io.*; ux-/>enc
evJ4C#Pr
iO{hA
public class FileAccessI implements Serializable{ Yu/ID!`Z
krxo"WgD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 OG~gFZr)6
RandomAccessFile oSavedFile; u2I*-K
long nPos; r+!YIk
\<h0Q,e
-/B+T>[nTb
public FileAccessI() throws IOException Z3e| UAif
{ /V8#[9K
this("",0); yqs4[C
} C.:<-xo
u]wZQl#-
.8g)av+
public FileAccessI(String sName,long nPos) throws IOException ~%F9%=
{ !.$I["/=
oSavedFile = new RandomAccessFile(sName,"rw"); 9)yJ: N#F
this.nPos = nPos; .~db4d]
oSavedFile.seek(nPos); KM0ru
} L<S9
qArM|\l1
*U-4Sy
public synchronized int write(byte[] b,int nStart,int nLen) ~Gp[_ %K
{ .<?GS{6 N
int n = -1; CT@ jZtg0
try{ 8,Z_{R#|
oSavedFile.write(b,nStart,nLen); Tb}4wLu
n = nLen; Rh2+=N<X
} ]]![EHi(\
catch(IOException e) TprTWod2]t
{ M.D1XX1/
e.printStackTrace (); 1nM #kJ"
} R-wp9^
;}WeTA_-[
mUC)gA/
return n; PQt")[
} Mt|zyXyzX
f)rq%N &
o|^3J{3G
} S72+d%$
YaqR[F
k}CVQ@nd
/* @IKYh{j4
**SiteInfoBean.java V-P#1Kkh
*/ ;;Y!^^g
package NetFox; pX<`+t[
atH*5X6d
7"D",1h
public class SiteInfoBean { ]%SH>
(Rh,,
_ye |Y
private String sSiteURL; //Site's URL /N+dQe
private String sFilePath; //Saved File's Path @7c?xQVd$
private String sFileName; //Saved File's Name mIvx1_[
private int nSplitter; //Count of Splited Downloading File =?*!"&h
"cGk)s
N% B>M7-=
public SiteInfoBean() wu6;.xTLl
{//nSplitter的缺省值为5 8rGgF]F
//default value of nSplitter is 5 e]aDP1n3t
this("","","",5); wm@@$
} j_[tu!~
+E+p"7
",t?8465y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) **0~K";\
{ sdrfsrNvB-
sSiteURL= sURL; ]cvwIc">
sFilePath = sPath; xu%k~4cB,
sFileName = sName; 9RL`<,Q
this.nSplitter = nSpiltter; aK~8B_5k8
8`{:MkXP
(m}'4et~L
} }#+^{P3;
dQX6(Jj
v~C Czg
public String getSSiteURL() :4w ?#
{ U>SShpmZA
return sSiteURL; Vt~{Gu-Y
} }6~hEc*/"
M0"_^?
y<3-?}.aZ
public void setSSiteURL(String value) #z%fx
{ est9M*Fn
sSiteURL = value; RBd7YWo\|j
} 8W7J3{d
On?v|10r'
l&zilVVm
public String getSFilePath() >|=ts
{ H41?/U,{
return sFilePath; 6_;icpN]
} Qel9G($=
hZ,_6mNg
I 34>X`[o
public void setSFilePath(String value) a-tmq]]E
{ @1j
sFilePath = value; QIEJ6`
} #X$\&,Yn"
W@IQ^ }E
,qwuLBW
public String getSFileName() ue"~9JK.
{ ATyEf5Id_
return sFileName; lVa%$F{Pq
} j;r-NCBnz
{Xy5pfW Q
4_lrg|X1
public void setSFileName(String value) 1I6px$^E\
{ Y@iS_lR
sFileName = value; .Hm>i
} >:!5*E5?
/nsX]V6i
pki%vRY
public int getNSplitter() r5/0u(\LB
{ FV!q!D
return nSplitter; T::85
} \@zHON(
gJ{)-\
Fo_sgv8O<
public void setNSplitter(int nCount) ~?}Emn;t
{ ~~P5k:
nSplitter = nCount; kTB0b*V
} C) s5D
} n@i HFBb
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>=>2m2z=
/* v?$:@9pAk
**Utility.java JbbzV>
*/ ,0sm
package NetFox; qDIZJh
U)gH}0n&
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public class Utility { _VN?#J)o
3"i-o$P
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public Utility() ObS3 M
{ L*+@>3mu)
ITBE|b
p l0\2e)
} /6*42[r
+'a^f5
//线程睡眠 !pW0qX\1n
public static void sleep(int nSecond) d0ksG$
{ /~?*=}c^m
try{ GxxW&y
Thread.sleep(nSecond); %> eiAB_b
} 2zb"MEOS5
catch(Exception e) j^JPZ{ej?
{ t*u:hex
e.printStackTrace (); +6\Zj)
} n\53wh@+
} W!(zT6#
Sm|6 %3
//日志 AkV#J, 3LC
public static void log(String sMsg) eMsd37J
{ u#.2w)!D
System.err.println(sMsg); 9A=,E&
} 4HlQ&2O%#
IJ"q~r$
(A#^l=su
public static void log(int sMsg) VONDc1%ga
{ eauF~md,
System.err.println(sMsg); zF<R'XP
} z:*|a+cy
} D,feF9
,qxu|9L
bn5 Su=]
/* 25?6gu*Z
**TestMethod.java HZge!Yp<
*/ Lf&kv7Wj
package NetFox; bAMdI 5Zk?
+e``OeXog
L,!?Nt\
public class TestMethod { GTd,n=
.k !{*
{wKB;?fUvk
public TestMethod() (<9u-HF#
{ ///xx/weblogic60b2_win.exe ]=BB#
try{ [W&T(%(W-
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S9.o/mr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 77Dn97l)&
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7@Qcc t4A
fileFetch.start(); ZECfR>`x
} e^voW"?%
catch(Exception e){e.printStackTrace ();} <5051UEu
2+XAX:YD
ygcm|PrS
} MQ2}EY*A
upmx $H>
&D<yX~
public static void main(String[] args) z{QqY.Gu{G
{ 75lA%| *X
new TestMethod(); N!}f}oF
} g_bLl)g<
} ]-#DB^EQ
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