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)); wBj-m
} 2|iV,uJ&
for(int i=0;i<nEndPos.length-1;i++) \2-@'^i
{ Yj|eji7y
nEndPos = nStartPos[i+1]; Vgb *% I
} AI vXb\wL
nEndPos[nEndPos.length-1] = nFileLength; 1+;C`bnA
} Xl7aGlH
} M,5j5<7
d$ACDX2
g1E~+@
//启动子线程 *.-.iY.a]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1F8 W9b^D
for(int i=0;i<nStartPos.length;i++) f"u*D,/sS
{ <:>SGSE9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &GTI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3f Xv4R;!:
nStartPos,nEndPos,i); \`V$ 'B{.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '7Nr8D4L
fileSplitterFetch.start(); Cb t{H}I3
} ]M>9ULQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F7L&=K$2y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d6{Gt"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f*{ YFg?*&
nEndPos = " + nFileLength); sxKf&p;
// fileSplitterFetch[nPos.length-1].start(); ?^mi3VM
`nXVE+E@
/^{BUo
//等待子线程结束 7\zZpPDV
//int count = 0; c\6+=\
//是否结束while循环 bi y4d
boolean breakWhile = false; =h6 sPJ
lE8&..~l$+
qSqI7ptA\
while(!bStop) 1 2++RkL#
{ up3O|lj4
write_nPos(); V-I(WzR9y
Utility.sleep(500); XfE?C:v
breakWhile = true; lU^;Z6f
{CG_P,FO
3nZ9m
for(int i=0;i<nStartPos.length;i++) ev0oO+u
{ f %lD08Sl
if(!fileSplitterFetch.bDownOver) Sd/?&
{ "vYE+
breakWhile = false; @l1
break; +x?#DH-
} $8USyGi3J
} m=AqV:%|
if(breakWhile) *%w69#D
break; Ut-B^x)gl
{qW~"z*
P&d"V<
//count++; b*;"q9u5
//if(count>4) 2$_9cF Wm
// siteStop(); w;}@'GgL
} `~eX55W
b `2|I {
;4M><OS!
System.err.println("文件下载结束！"); a07@C
} +uWDP.
catch(Exception e){e.printStackTrace ();} "'8KV\/D
} .@-9'<K?~
ML-)I&>tT
|4mpohX
//获得文件长度 !Fw?H3X!"q
public long getFileSize() KfBTL!0#
{ _rV5E
int nFileLength = -1; S-31-Zjw
try{ >-_d CNZ
URL url = new URL(siteInfoBean.getSSiteURL()); id<:p*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BR^7_q4q
httpConnection.setRequestProperty("User-Agent","NetFox"); y-p70.'{U
x\&`>>uA
^_5L"F]sP
int responseCode=httpConnection.getResponseCode(); ihh4pD27g
if(responseCode>=400) Q9d`zR]
{ MS(JR
processErrorCode(responseCode); k4qp u=@U
return -2; //-2 represent access is error \Gm-MpW
} %p^.\ch9
>e2<!#er|
R(P%Csbqh
String sHeader; $Y=T&O
:+{ ?
-U<Upn)2
for(int i=1;;i++) e{;OSk`x
{ 1:NrP'W^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =NbI%
//Utility.log(in.readLine()); a9n^WOJ6
sHeader=httpConnection.getHeaderFieldKey(i); qQpnLV4
if(sHeader!=null) (>mI'!4d
{ t E` cau
if(sHeader.equals("Content-Length")) /&u<TJ4
{ N=:5eAza
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0JgL2ayIVI
break; ^mAYBOE
} ]0;864X0
} 2j(h+?N7k
else ] 2DH;
break; ZYf2XI(_"
} U.AjYez
} -",=G\XZ
catch(IOException e){e.printStackTrace ();} y%sroI('y
catch(Exception e){e.printStackTrace ();} {k4CEt;
UA[,2MBp
r1ws1 rr=
Utility.log(nFileLength); wU#F_De)R:
k>dsw:
V`adWXu
return nFileLength; h8\ T
} th6+2&B6
Qn ^bVhG+
iv phlw
//保存下载信息（文件指针位置） n~g)I&
private void write_nPos() 0Io'bF
{ LPG`^SA
try{ #jAqra._b
output = new DataOutputStream(new FileOutputStream(tmpFile)); UgWs{y2SE.
output.writeInt(nStartPos.length); nR4y`oP+
for(int i=0;i<nStartPos.length;i++) :{NC-%4o0
{ }SIGPVM
// output.writeLong(nPos); =9kN_:-
output.writeLong(fileSplitterFetch.nStartPos); h._nK\
output.writeLong(fileSplitterFetch.nEndPos); k{gLMl
} :K\mN/ x
output.close(); O62b+%~F
} pV6d Id
catch(IOException e){e.printStackTrace ();} K1V#cB WO
catch(Exception e){e.printStackTrace ();} Z/^ u
} &a/__c/l
5Z4-Z
zEZLKWm9-
//读取保存的下载信息（文件指针位置） LZ@|9!KDw
private void read_nPos() &z"krM]G
{ jCTAKaq
try{ +0),xu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;['[?wk
int nCount = input.readInt(); d:G]1k;z
nStartPos = new long[nCount]; I@Xn3oN
nEndPos = new long[nCount]; O]f/r,4@
for(int i=0;i<nStartPos.length;i++) \rykBxs
{ 0Z|FZGRP
nStartPos = input.readLong(); pZ#ap<|>I
nEndPos = input.readLong(); v/*Y#(X
} 2<mW\$
input.close(); sH[ -W-
} I\qYkWg7
catch(IOException e){e.printStackTrace ();} @aQ1khEd
catch(Exception e){e.printStackTrace ();} y~IuPc
} yL;M"L
c9R5w.t:
UpXz&k
private void processErrorCode(int nErrorCode) \7"@RHcihB
{ y7KzW*>g:
System.err.println("Error Code : " + nErrorCode); ~2EHOO{
} e!fqXVEVR
65ly2gl
(M =Y&M'f
//停止文件下载 m]*Bx%-1c
public void siteStop() vK$"# F~
{ 9dMrgz&'
bStop = true; :';L/x>
for(int i=0;i<nStartPos.length;i++) cI]WrI2CQa
fileSplitterFetch.splitterStop(); ?Qb<-~~ j1
l{w#H|]
smG>sEp2
} _2btfY1U
} LQnkcV
//负责部分文件的抓取 10#oG{9
**FileSplitterFetch.java +.y .Mp
*/ \D>$aLO*?
package NetFox; MxzLK%am
Knhp*V?
?^:h\C^a"
import java.io.*; vpPl$ga5bY
import java.net.*; E,n}HiAz7V
Y^%T}yTtq
n;R#,!<P
public class FileSplitterFetch extends Thread { `si#aU
Oi"a:bCU
7FN<iI&7\
String sURL; //File URL W4;m H}#0
long nStartPos; //File Snippet Start Position /v095H@
long nEndPos; //File Snippet End Position .oEmU+
int nThreadID; //Thread's ID X0{/ydGF8
boolean bDownOver = false; //Downing is over k`".
boolean bStop = false; //Stop identical nN$Y(2ZN
FileAccessI fileAccessI = null; //File Access interface 8Ry74|`=R
Ax oD8|
M5T9JWbN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @DW[Z`X
{ OL7_'2_z.
this.sURL = sURL; HE<1v@jW
this.nStartPos = nStart; ,:+dg(\r
this.nEndPos = nEnd; +.RKi!
nThreadID = id; ]4+s$rG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9;yn}\N `
} 6io, uh!
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-st7_3
public void run() _ >`X]I;
{ Hn,:`mj4-6
while(nStartPos < nEndPos && !bStop) K.gEj*@
{ @?C#r.vgp
* y^OV_n-8
,2oF:H
try{ R~bC,`Bh
URL url = new URL(sURL); ,n!vsIN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a:~@CUD >I
httpConnection.setRequestProperty("User-Agent","NetFox"); )hwV`2>l
String sProperty = "bytes="+nStartPos+"-"; 7j5f ;O^+
httpConnection.setRequestProperty("RANGE",sProperty); s=?aox7
Utility.log(sProperty); Bh&Ew
W"L&fV+3
JcJmds
InputStream input = httpConnection.getInputStream(); %iJ%{{f`
//logResponseHead(httpConnection); (2?G:+C 7
W:i?t8y\y
P7B:%HiAx
byte[] b = new byte[1024]; Qy#)Gxp
int nRead; wV?,Z!\Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3M5#4n\v$
{ }U@m*dEG
nStartPos += fileAccessI.write(b,0,nRead); UDf9FnG}L
//if(nThreadID == 1) c= UU"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bg|!'1bD`5
} f[gqT yiP
\Mv":Lm1
dQezd-y*
Utility.log("Thread " + nThreadID + " is over!"); Y}6n]n;uR
bDownOver = true; }awzO#
//nPos = fileAccessI.write (b,0,nRead); ?_\$
} (3\Xy
catch(Exception e){e.printStackTrace ();} 7dihVvL $
} QbhW!9(,
} H* !EP
%/kyT%1
G;gJNK"e
//打印回应的头信息 /R X1UQ.s
public void logResponseHead(HttpURLConnection con) DOm[*1@^
{ 3+MB5T
for(int i=1;;i++) `ir3YnT+
{ Ql?^ B SqG
String header=con.getHeaderFieldKey(i); y0v]N
if(header!=null) Oc9#e+_&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ct$82J
Utility.log(header+" : "+con.getHeaderField(header)); -6Tk<W
else @|bP+8oU
break; l2b{u GE
} R)!`JKeO/
} F{k+7Ftc
Dj-s5pAW
[%HIbw J
public void splitterStop() ,]R8(bD)
{ 3E} An%
bStop = true; 8:ggECD
} us?&:L|!=
ba@ax3
%IL6ix
} kfC0zd+
>KGE-Yzj
B1N)9%
/* ^[TV;9I*
**FileAccess.java !- C'}
*//文件访问(定位，写) b hjZ7=
package NetFox; "$p#&W69"J
import java.io.*; H;<!TX.zD
HU B|bKy
#nyv+x;
public class FileAccessI implements Serializable{ ~WVO
gL$&@NY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]/]ju$l9Z
RandomAccessFile oSavedFile; ,S[K{y<
long nPos; Bt^K]F\
~>ME'D~
%@&a7JOL
public FileAccessI() throws IOException OQ_stE2i
{ +2cs#i
this("",0); bggusK<
} WoL9V"]
B_3QQtjAl
pLoy
public FileAccessI(String sName,long nPos) throws IOException "5DJu~
{ V7CoZnz
oSavedFile = new RandomAccessFile(sName,"rw"); vTr34n
this.nPos = nPos; A,i()R'I
oSavedFile.seek(nPos); vfvlB[
} <FFJzNc+
lHBI
O]u",J5
public synchronized int write(byte[] b,int nStart,int nLen) 7r{qJ7$%
{ kL{;.WsB
int n = -1; 4dhqLVgL{
try{ 2iXoj&3e
oSavedFile.write(b,nStart,nLen); K6\` __mLf
n = nLen; 34C``i
} u7]<=*V]
catch(IOException e) _45cH{$sA
{ O@U?IF$
e.printStackTrace (); ,^T]UHRO
} $B\E.ml.
|:iEfi]j
N}/>rD
return n; 8q_0,>w%
} 1/j$I~B
T@+ClZi
10N,?a
} u?Hb(xZtg=
nW;kcS*A
3_ 2hC!u!K
/* VAj<E0>
**SiteInfoBean.java &/F_*=VE
*/ 3l:QeZ
package NetFox; B#N7qoi
.Oo/y0E^
&{^eU5
public class SiteInfoBean { XDmbm*~i
P[gO85
v+q<BYq
private String sSiteURL; //Site's URL hYt7kq!"
private String sFilePath; //Saved File's Path >S&U.
private String sFileName; //Saved File's Name 4\Di,PPu
private int nSplitter; //Count of Splited Downloading File ?9?4p@
e9@(/+
R8sck)k'}
public SiteInfoBean() tW6#e(^l6
{//nSplitter的缺省值为5 u*R7zY
//default value of nSplitter is 5 K^D82tP
this("","","",5); a|x8=H
} A!HK~yk~Q
V:^H4WvL\W
9`X&,S~e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }""p)Y&
{ W7e4pR?w
sSiteURL= sURL; O k(47nC
sFilePath = sPath; c>MY$-PD
sFileName = sName; )mD\d|7f
this.nSplitter = nSpiltter; pDDG_4E>
!RMS+Mm?
h%b hrkD
} fGO*%)
g5}7y\
FN{/.?w(
public String getSSiteURL() >ZCo 8aK
{ cIZc:
return sSiteURL; FLbZ9pX}
} Baq ~}B<
[}k|
x`2pr
public void setSSiteURL(String value) x70N8TQ_gK
{ -uR{X G. D
sSiteURL = value; mTd<2Hy
} NG-`ag`s
YRa4W.&Yn
[t}):}~F|
public String getSFilePath() 2]Fu 1
{ GVp
return sFilePath; hmzair3X
} -Op@y2+c
c,BAa*]K
j;0ih_Z@4W
public void setSFilePath(String value) iPFL"v<#J
{ |0w~P s
sFilePath = value; 7 6*hc
} m+$/DD^-zl
&!#2ZJ}{
[f(uqLdeM
public String getSFileName() 1Zq
{ $~hdm$
return sFileName; /,t| !)\]
} '}zT1F* p=
*^6k[3VY
nOuN|q=C
public void setSFileName(String value) TAAR'Jz S
{ >C^/,/%v
sFileName = value; 0# UAjT3
} P%jkKE?B4
?1DUNZ6
wz@/5c/u
public int getNSplitter() +9~ZA3DiP
{ !h/dZ`#
return nSplitter; % &+|==-
} qa;EI ;8
Xa*?<(^`
'Aet{A=9
public void setNSplitter(int nCount) A?sNXhh
{ g\j>qUjs%Q
nSplitter = nCount; C&oxi$J:p+
} V%o#AfMI_
} 6NSO>/E
*vXDuhQ
<tU :U<ea]
/* ZU^Q1}</5
**Utility.java A ')(SGSc
*/ 5 2fO)!
package NetFox; m^Rd Iy)
o] S`+ZcV
Lqq*Nr
public class Utility { B,:23[v
-MUQ\pZ
k$?&]! <o
public Utility() K.r!?cfv
{ mR6E]TuM
P69>gBZYD
s|KfC>#
} D~7%};D[
y#nSk%"t"
//线程睡眠 w0\4Wa
public static void sleep(int nSecond) n<+~ zQ
{ iF+S%aPd#
try{ M Yu?&}%^
Thread.sleep(nSecond); WY3_7k8u
} %!D_q~"H
catch(Exception e) &F9OZMK=
{ 0rGj|@+;
e.printStackTrace (); yCZ2^P!a
} ]~ >@%v&
} ?<g|.HY/
@ > cdHv
//日志 @t "~
public static void log(String sMsg) Y9/{0TArG
{ S]tkz*w0*
System.err.println(sMsg); &~42T}GTWG
} =CGD ~p`
EOofa6f&l
6@i|Kw(:
public static void log(int sMsg) SG1&a:c+.
{ es{cn=\s
System.err.println(sMsg); <)=3XEcb
} `f2W;@V0
} j#4+-
Cbazwq
eR(\s_`
/* sf<Q#ieTxY
**TestMethod.java Ixyvn#ux)
*/ Bd/} %4V\@
package NetFox; N,h1$)\B#
VM=hQYe
{_?T:`
public class TestMethod { qAnA=/k`
PjiNu.>2(
t00\yb^vJ8
public TestMethod() |C&%S"*+D
{ ///xx/weblogic60b2_win.exe U#OWUZ
try{ BYkVg2D(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Qo]vpp^[#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Xv`2hf
SiteFileFetch fileFetch = new SiteFileFetch(bean); XPGL3[w\V
fileFetch.start(); 0EcC
} .G7]&5s
catch(Exception e){e.printStackTrace ();} &?}kL= h
5B8V$ X
TW'E99wG
} dcV,_
{d&X/tT
)er?*^9Z
public static void main(String[] args) hP,b-R9\
{ j;$6F/g
new TestMethod(); ]J8KCjq@
} G5y]^P
} 82G lbd)
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