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)); `} :~,E
} ,G!mO,DX
for(int i=0;i<nEndPos.length-1;i++) u<K{=94!e
{ h\PybSW4s
nEndPos = nStartPos[i+1]; Xhm)K3RA*T
} RoeLf Ow
nEndPos[nEndPos.length-1] = nFileLength; e{7"7wn=
} qASV\ <n
} GMQKR,6VM
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gWpG-RL0
//启动子线程 T6N~L~J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A,#a?O6m
for(int i=0;i<nStartPos.length;i++) +o^sm'$
{ UJhUb)}^
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'NDDj0Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 31=vUS
nStartPos,nEndPos,i); _&|<(m&."
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %r >Y)@$Vt
fileSplitterFetch.start(); m vLqccL
} N4[^!}4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `}|$eF&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `as6IMqJD
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kli)6R<
nEndPos = " + nFileLength); T@x_}a:g
// fileSplitterFetch[nPos.length-1].start(); <n{-&;>
KB6`OT^b{r
ooIA#u
//等待子线程结束 4oA9|}<FR
//int count = 0; tB==v{t
//是否结束while循环 !<W^Fh
boolean breakWhile = false; diDB>W
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~#y(]Xec2
while(!bStop) V4qv7
{ &n-)Alx
write_nPos(); Z]x)d|3;
Utility.sleep(500); uhO-0H
breakWhile = true; 35PIfqm
#AUV&pI[
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for(int i=0;i<nStartPos.length;i++) S^*ME*DDz
{ 3KN>t)A#
if(!fileSplitterFetch.bDownOver) g]Fm%iy
{ 8KyF0r?
breakWhile = false; d<+@cf_9
break; {&d )O
} `;\~$^sj}
} ]0@ 06G(y
if(breakWhile) lz88//@gZ
break; b?deZ2"L#
4NxI:d$&*
ePxwN?
//count++; *e}1KcJ
//if(count>4) -G@:uxB
// siteStop(); _rjB.
} 6qH^&O][
=%ZR0cWPoI
:]+p#l
System.err.println("文件下载结束！"); O)?
} M&~cU{9c
catch(Exception e){e.printStackTrace ();} !(>yB;u
} .Mu]uQUF
)W.Y{\D0
32Jl|@8,g
//获得文件长度 S1G3xY$0
public long getFileSize() mj_V6`m4
{ 6V^KOG
int nFileLength = -1; oES4X{,
try{ mH)th7
URL url = new URL(siteInfoBean.getSSiteURL()); z;+LU6V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cNvh2JI
httpConnection.setRequestProperty("User-Agent","NetFox"); zPt0IB_j'
UVj1nom
F`U YgN
int responseCode=httpConnection.getResponseCode(); $1bx\
if(responseCode>=400) %;qDhAu0
{ f$p7L.d<
processErrorCode(responseCode); xA {1XS}
return -2; //-2 represent access is error )!jX$bK
} &p6^
ztHEXM.
~zD*=h2C
String sHeader; 7R5!(g
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F,>-+~L=
for(int i=1;;i++) tDwj~{a~
{ A.@Af+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rJqRzF{|P6
//Utility.log(in.readLine()); 8jz[;.jP",
sHeader=httpConnection.getHeaderFieldKey(i); 9d1 Gu"
if(sHeader!=null) 7UA|G2Zr
{ j3yz"-53e
if(sHeader.equals("Content-Length")) ZK8I f?SD
{ rN5;W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JwMFu5@
break; [$P.ek<
} \jGvom.
} BLQD=?Q
else ^":Dk5gl
break; Jk3V]u
} OJ2I (8P
} KuohUH+
catch(IOException e){e.printStackTrace ();} 9HJA:k*k|
catch(Exception e){e.printStackTrace ();} #RWHk
O| zLD
4C[n@p2
Utility.log(nFileLength); hDc)\vzr
[tY+P7j9)
Yvbk[Rb
return nFileLength; [5O`
} k>;a5'S
z3>oUq{
/'g"Ys?3
//保存下载信息（文件指针位置） y.m;4((
private void write_nPos() S+Vsy(
{ {%Ujp9i
try{ I'%(f@u~
output = new DataOutputStream(new FileOutputStream(tmpFile)); D"RxI)"HP
output.writeInt(nStartPos.length); ~A =?_5kJ
for(int i=0;i<nStartPos.length;i++) 5xF R7%_&
{ 'YUx&FcM
// output.writeLong(nPos); sM8AORd
output.writeLong(fileSplitterFetch.nStartPos); k9iXVYQ.;r
output.writeLong(fileSplitterFetch.nEndPos); baL-~`(T
} e+=IGYC
output.close(); {pof=G
} y$^.HI02jP
catch(IOException e){e.printStackTrace ();} OP}8u"\Z
catch(Exception e){e.printStackTrace ();} l5bd);Ltq
} ^vH3 -A;*
? (f44Zgm
j*05!j<'
//读取保存的下载信息（文件指针位置） 6a\YD{D] _
private void read_nPos() dxIt.h
{ `GD>3-
try{ WCPl}7>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KB^i=+xr
int nCount = input.readInt(); |#D$9+
nStartPos = new long[nCount]; fW'U7&O
nEndPos = new long[nCount]; 999E0A$dkv
for(int i=0;i<nStartPos.length;i++) M$Of.
{ ~0~f
nStartPos = input.readLong(); (xhwl=MX)
nEndPos = input.readLong(); :5M7*s)e16
} xHMbtY
input.close(); `!$I6KxT
} (`&`vf
catch(IOException e){e.printStackTrace ();} xjDV1Xf*
catch(Exception e){e.printStackTrace ();} x3>PM]r(V
} 1~#2AdG
g~AOKHUP
8x J]K
private void processErrorCode(int nErrorCode) +5BhC9=b
{ w 9mi2=
System.err.println("Error Code : " + nErrorCode); '9#O#I&J
} 3_]<H<w
k)a-odNrb
L--(Y+vmf
//停止文件下载 s s*% 3<
public void siteStop() l[EjtN
{ MXj7Z3
bStop = true; rHWlv\+Nn
for(int i=0;i<nStartPos.length;i++) }`,}e259
fileSplitterFetch.splitterStop(); oIP<7gz
utvZ<zz`
2"~QI xY=
} oT\u^WU
} -b4#/q+bb+
//负责部分文件的抓取 LJ|2=lI+jb
**FileSplitterFetch.java AShnCL8uR
*/ a|x1aN0
package NetFox; {G D<s))
2AAZZx +$
De(\<H#
import java.io.*; ?(^HjRUY
import java.net.*; j5EZJ`
~$8t/c
hF!t{ Lf3
public class FileSplitterFetch extends Thread { !P&F6ViO=
U Ux]
s2{d<0x?v
String sURL; //File URL ?1?zmaS
long nStartPos; //File Snippet Start Position 0DBA 'Cv
long nEndPos; //File Snippet End Position `KgWaf-
int nThreadID; //Thread's ID Y70[Nz
boolean bDownOver = false; //Downing is over bJo)rM:m
boolean bStop = false; //Stop identical 65ctxxWv1
FileAccessI fileAccessI = null; //File Access interface 9aR-kcvJIJ
9$z|kwU
.#,!&Lt
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G' ~Z'
{ mOb*VH
this.sURL = sURL; 5UQz6DK
this.nStartPos = nStart; [`~E)B1Y
this.nEndPos = nEnd; >h0iq
nThreadID = id; R`wL%I!?f
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pb(YA/
} zw`T^N#
c7[<X<yk
)Qe4J0.
public void run() Nd.+Rs
{ gJ_{V;R
while(nStartPos < nEndPos && !bStop) /R@,c B=
{ GnlP#;
kgX"LQh;[G
P9)E1]Dc$
try{ Z.b}
URL url = new URL(sURL); iwnctI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zr0bVe+h
httpConnection.setRequestProperty("User-Agent","NetFox"); B>3joe}
String sProperty = "bytes="+nStartPos+"-"; Zz<k^
httpConnection.setRequestProperty("RANGE",sProperty); hpD\,
Utility.log(sProperty); y\DR,$Py
9 wun$!>&
F_9eju^|
InputStream input = httpConnection.getInputStream(); El;\#la
//logResponseHead(httpConnection); 6q[|U_3I@
(cX;a/BR
k !S0-/h
byte[] b = new byte[1024]; <n4T*
int nRead; 2nW:|*:/p6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3[g%T2&[
{ S <C'#vj
nStartPos += fileAccessI.write(b,0,nRead); p&SxR}h
//if(nThreadID == 1) j~(s3pSCo
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _;G. QwHr
} #,0PLU3%
N02X*NC
x=g=e <_
Utility.log("Thread " + nThreadID + " is over!"); ^tS{a*Yn
bDownOver = true; 2sj[hI
//nPos = fileAccessI.write (b,0,nRead); I%]~]a
} jN\} l|;q
catch(Exception e){e.printStackTrace ();} 'u6T^YS
} 3BuG_ild
} _d#1muZ?p|
WgxGx`Y)
'?Mt*%J@=$
//打印回应的头信息 'D ,efTq
public void logResponseHead(HttpURLConnection con) Yv?nw-HM
{ S+^*rw
for(int i=1;;i++) vUEG0{8l
{ t$NK{Mw5_
String header=con.getHeaderFieldKey(i); /gkHV3}fu
if(header!=null) :+%"kgJNL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EZy:_xjZ
Utility.log(header+" : "+con.getHeaderField(header)); AJ_''%$I3:
else Zj@k3y
break; Arg604V3
} ~)\9f 1O{^
} A"(XrL-pV
9yU(ei:GUo
:6k8\{^9"D
public void splitterStop() RRW/.y
{ u@j]U|FpY
bStop = true; )HHG3cvU
} fqoI(/RWP
{MP8B'r-6
lSGtbSyDI
} toDv~v
3uSj5+@q6
td*1
/* i3bH^WwE&k
**FileAccess.java ?b?6/_W~R
*//文件访问(定位，写) ({XB,Rm
package NetFox; h<)YZ[;x
import java.io.*; nQe^Bn
o~Jce$X
!t.
public class FileAccessI implements Serializable{ F];"d0O#5
ZY_aE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F E`4%X
RandomAccessFile oSavedFile; v2OK/W,0
long nPos; V}?*kx~T2C
+m|S7yr'
-~ w5yd
public FileAccessI() throws IOException 8+HXGqcv
{ HPz9Er
this("",0); 7R4sd
} :{:R5d(_I
%sd1`1In
s(~tL-_ K
public FileAccessI(String sName,long nPos) throws IOException xF:}a:c@H
{ =ttvC"4?
oSavedFile = new RandomAccessFile(sName,"rw"); G~z=,72
this.nPos = nPos; K90wX1&
oSavedFile.seek(nPos); PxuE(n V[
} e"^ /xF
xEW>7}+\
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public synchronized int write(byte[] b,int nStart,int nLen) 1~J:hjKQ
{ DdUT"%
int n = -1; (T290a9y>
try{ MK"p~b0->
oSavedFile.write(b,nStart,nLen); Ue:LKK1Gsr
n = nLen; ]]sy+$@~
} (R'GrN>
catch(IOException e) mEL<d,XhI
{ .<#oLM^
e.printStackTrace (); yf > rG
} d-GU164
,iUWLcOM
;rp("<g:>
return n; {..6{~L
} Alo;kt@x
w'[^RZW:j
C?xah?Sk
} ElFiR;
$#z ` R;
l(irNKutgo
/* @ Sq =q=S
**SiteInfoBean.java XZh1/b^DMN
*/ 1/JtL>SKE
package NetFox; 9i6z p'
$-J0ou8~
x9DG87P~+
public class SiteInfoBean { rI'kGqU
B=?m_4\$m
*Z9Rl>
private String sSiteURL; //Site's URL DGc5Lol~
private String sFilePath; //Saved File's Path hSl6X3W
private String sFileName; //Saved File's Name O V"5:){
private int nSplitter; //Count of Splited Downloading File `;`fA|F^
$Ph T:
teQ<v[W.
public SiteInfoBean() OON]E3yy
{//nSplitter的缺省值为5 *KMW6dg;
//default value of nSplitter is 5 =,MX%-2
this("","","",5); 8;%F-?
} 1<9=J`(H
b0(bL_,
`>HM<Nn-0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @IXvp3r
{ j3-^,r t4
sSiteURL= sURL; /JqNiqvh
sFilePath = sPath; >'eY/>n{
sFileName = sName; {wp~
this.nSplitter = nSpiltter; +hIC N,8!
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!#NGGIp;
} MD4RSl<F
h^B~Fv>~
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public String getSSiteURL() w\K(kNd(
{ Wr j<}L|
return sSiteURL; 5bj9S
} Zra P\?
pu"m(9
U} K]W>Z
public void setSSiteURL(String value) G?,b51"
{ <MQTOz oj
sSiteURL = value; JEL.*[/
} >s%&t[r6
6_=t~9sY
B4#XQ-
public String getSFilePath() P&snIJ
{ dED&-e#
return sFilePath; vY"i^a`f
} 'NAC4to;;
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&6@#W]_
public void setSFilePath(String value) zObrp
{ TOH+JL8L
sFilePath = value; srGF=1_
} (nDen5Q|
CMiE$yC
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public String getSFileName() nOm-Yb+F
{ V[#$Sz[G
return sFileName; 8[B0[2O
} K ; eR)
Y00hc8<
"y7IH GJ\3
public void setSFileName(String value) 4!U)a
{ lf9mdbm
sFileName = value; }m -A #4.
} Lz/{ q6>
p Lwtm@
olxnQYFo
public int getNSplitter() FoW|BGA~
{ xbNL <3"a
return nSplitter; <*3#nA-O>i
} '}, 8x?
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public void setNSplitter(int nCount) VkD}gJY
{ Q`zW[Y&]
nSplitter = nCount; =K;M\_k%y
} (7 O?NS
} 8-s7s!j
=M."^X
DX(!G a
/* 8dUP_t~d#q
**Utility.java OnND(YiX
*/ 2EC<8}CG
package NetFox; B1k;!@@14
}8Yu"P${Y
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public class Utility { hQ80R B
:>*0./hG
M\D25=(
public Utility() x>GxyVE
{ le150;7
^JY,K
pmuT7*<19
} DmiZ"A
=`OnFdI
//线程睡眠 Fql|0Fq
public static void sleep(int nSecond) `9&~fWu
{ y[DS$>E
try{ oC~+K@S
Thread.sleep(nSecond); VT2f\d[Q
} mIW/x/I
catch(Exception e) Xk9 8%gv
{ 'pHxO,vo
e.printStackTrace (); y4N2gBTKu
} il[waUfmD
} `6\u!#
`&jG8lHa
//日志 U.pGp]\Q)G
public static void log(String sMsg) >zV
{ ly::?
System.err.println(sMsg); 6=p!`DOd
} h'"~t#r
hH~GH'dnaE
2v`Q;%7O
public static void log(int sMsg) s-Qq#T
{ kLe{3>}j
System.err.println(sMsg); 6^sH3=#
} i'3)5
} b6d}<b9#
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M-/2{F[
/* #]*]qdQWV^
**TestMethod.java NJmyp!8
*/ X@\ 9}*9
package NetFox; [{.9#cQ"
t[p/65L>8
@;7Ht Z`
public class TestMethod { 9R99,um$
^[.Z~>3!\q
=\IUBH+C
public TestMethod() ke19(r Ch
{ ///xx/weblogic60b2_win.exe M~g{}_0Z
try{ Xu7lV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NL-V",gI-~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y'Yu1mH)
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5Bp>*MR/".
fileFetch.start(); 9dFo_a*?
} FyqsFTh_
catch(Exception e){e.printStackTrace ();} P-\65]`C
3'!*/UnU
N6BEl55 &
} I.- I4F)D
S{nBQB<
T:3}W0s,
public static void main(String[] args) ;{1 ws
{ :KI0j%>2y
new TestMethod(); h$#|s/
} 4ah5}9{g
} vRLWs`1j
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