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)); *&rV}vVP^
} 5@{~830
for(int i=0;i<nEndPos.length-1;i++) KvuM{UI5
{ B7nm7[V
nEndPos = nStartPos[i+1]; )zvjsx*e=J
} O}q(2[*i
nEndPos[nEndPos.length-1] = nFileLength; ^%m~VLH
} jo[U6t+pj7
} ?bl9e&/!
B3V+/o6
-^= JKd&p
//启动子线程 j9$kaEf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8jU6N*p/
for(int i=0;i<nStartPos.length;i++) 5Q@4@b{C
{ Ia*T*qJu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -v?)E S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^uWj#
nStartPos,nEndPos,i); n.xOu`gj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t$b{zv9C
fileSplitterFetch.start(); OT}^dPQe
} 0`"DYJ}d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RV, cQ K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MF.$E?_R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c:_dW;MJ0
nEndPos = " + nFileLength); ;F\sMf{
// fileSplitterFetch[nPos.length-1].start(); Pxe7 \e
LkUi^1((e
yI_MYL[
//等待子线程结束 XQ$9E?|=
//int count = 0; <5sP%Fs)
//是否结束while循环 A<[X@o}92
boolean breakWhile = false; /3CdP'c
Zi ;7.PqL
VyxX5Lrj
while(!bStop) F=~LVaF/_
{ TvwkeOS#}7
write_nPos(); qM:*!Aq0g
Utility.sleep(500); A,! YXl[
breakWhile = true; bDM;7fFp$
P(Q}r7F~(
td\'BV
for(int i=0;i<nStartPos.length;i++) Z^ }4bR]
{ QF9$SCmv
if(!fileSplitterFetch.bDownOver) :A]CD(
{ s f<NC>-
breakWhile = false; Cc!LJ
break; ?/^x)Nm
} C+Pw
} ?4MZT5 .
if(breakWhile) +"Mlj$O
break; HWi: CDgm
_XUDPC(*qz
/7p1y v
//count++; w.R2' WR
//if(count>4) ETtoY<`#
// siteStop(); &Vmx<w
} $o>6Io|D
Ls(l
k2ZMDU
System.err.println("文件下载结束！"); 2, r{zJ8
} vy1N,8a
catch(Exception e){e.printStackTrace ();} lxXIu8
} @[w.!GW%
glgXSOj
-{s9PZ3~_
//获得文件长度 XT~]pOE;D
public long getFileSize() 3pI)
{ 299uZz}Y
int nFileLength = -1; %n:ymc $}
try{ pl5Q2zq%
URL url = new URL(siteInfoBean.getSSiteURL()); @rt}z+JF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W,sPg\G 3
httpConnection.setRequestProperty("User-Agent","NetFox"); UWg+7RL
<%EjrjdvL+
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int responseCode=httpConnection.getResponseCode(); \4roM1&[
if(responseCode>=400) u^]Z{K_B
{ !:9s>0';N
processErrorCode(responseCode); Q[UYNQ0w
return -2; //-2 represent access is error X(fT[A_2C
} _"'0^F$I
f l*O)r
H"J>wIuGX
String sHeader; A6%~+9
73>Hzpv0
MFO1v%m
for(int i=1;;i++) !DNk!]|
{ V( SRw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); SH#!Y
//Utility.log(in.readLine()); N2e]S8-
sHeader=httpConnection.getHeaderFieldKey(i); P~7p~ke
if(sHeader!=null) (`FY{]Wz!
{ - {|
if(sHeader.equals("Content-Length")) UA}N
{ |t&gyj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Kzf^ras4u
break; `beU2N
} W"ldQ
} $>!tpJw
else g"Gj8QLDz
break; |aMeh;X t
} `w/b];e1)
} D./3,z
catch(IOException e){e.printStackTrace ();} 2&d|L|->
catch(Exception e){e.printStackTrace ();} +a}>cAj*
DS6g_SS3
Onj)AJ9M0r
Utility.log(nFileLength); mUjM5ceAXO
V[baGNe
=Z}=nS?4
return nFileLength; ,1|0]:
} =X}s^KbI{
TOXZl3s5#
6`U]%qx_I
//保存下载信息（文件指针位置） vDp|9VY?
private void write_nPos() -Gmg&yQ9
{ n>i}O!agg
try{ muKCCWy#
output = new DataOutputStream(new FileOutputStream(tmpFile)); !0!r}#P
output.writeInt(nStartPos.length); TwLQ;Q
for(int i=0;i<nStartPos.length;i++) 7bC)Co#:
{ { K*
// output.writeLong(nPos); XD$;K$_7
output.writeLong(fileSplitterFetch.nStartPos); ?N(opggiD
output.writeLong(fileSplitterFetch.nEndPos); ;J&9l >
} <A@qN95m
output.close(); Ul%D}(,
} '(!U5j
catch(IOException e){e.printStackTrace ();} ;iTZzmB
catch(Exception e){e.printStackTrace ();} 19 <Lgr
} +N:=|u.g
LGPPyKNx
LQ3J$N
//读取保存的下载信息（文件指针位置） ^muPjM+D
private void read_nPos() `sPH7^R
{ J!@`tR-
try{ :zLeS-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .rs\%M|X
int nCount = input.readInt(); /w2jlu}yt
nStartPos = new long[nCount]; '
nEndPos = new long[nCount]; WDq~mi
for(int i=0;i<nStartPos.length;i++) QTT2P(Pz
{ $61j_;WF`
nStartPos = input.readLong(); A~%h*nZc%I
nEndPos = input.readLong(); +w'He9n
} %Tm8sQ)1
input.close(); B7ty*)i?
} 1_0\_|
catch(IOException e){e.printStackTrace ();} kH}HFl
catch(Exception e){e.printStackTrace ();} :to1%6
} FvT;8ik:3
&NB"[Mm:@
L|N[.V9
private void processErrorCode(int nErrorCode) n>aH7
{ 68,(+vkB
System.err.println("Error Code : " + nErrorCode); v JPX`T|
} x>m=n_
?fmW'vs
Ze-MB0w
//停止文件下载 B96"|v$
public void siteStop() ] R-<v&O
{ UTph(U#
bStop = true; n06Jg+
for(int i=0;i<nStartPos.length;i++) atmTI`i
fileSplitterFetch.splitterStop(); To@77.'
6BIr{SY
=%ZR0cWPoI
} 9G=HG={
} D;QV`Z%I
//负责部分文件的抓取 v!77dj 6I
**FileSplitterFetch.java WpPI6bd
*/ MMS#Ci=Lj
package NetFox; URb
[&h%T;!Qii
1J @43>u{
import java.io.*; :elTqw>pn
import java.net.*; kQQhZ8Ch
NQqq\h
0FG|s#Ig
public class FileSplitterFetch extends Thread { lJ/{.uK
h(MS>=
v7@O ,%
String sURL; //File URL @1^:V-=
long nStartPos; //File Snippet Start Position IM$I=5ye
long nEndPos; //File Snippet End Position C3GI?|b
int nThreadID; //Thread's ID }j6<S-s~
boolean bDownOver = false; //Downing is over gi5Ffvs$
boolean bStop = false; //Stop identical d6ABgQi0
FileAccessI fileAccessI = null; //File Access interface gPzp/I
2E_*'RT
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G;Thz
{ >C"QV`+
this.sURL = sURL; /{HK0fd
this.nStartPos = nStart; >J>|+W
this.nEndPos = nEnd; V07? sc<
nThreadID = id; 1H]E:Bq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &RbT&
} 'Bb@K[=s
aT`. e
2#g4R
public void run() 8jz[;.jP",
{ F}dq~QCzw
while(nStartPos < nEndPos && !bStop) 7UA|G2Zr
{ j3yz"-53e
QB|D_?]
rN5;W
try{ hD!9[Gb
URL url = new URL(sURL); >$dkA\&p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KM jnY2
httpConnection.setRequestProperty("User-Agent","NetFox"); )'Yoii{dSU
String sProperty = "bytes="+nStartPos+"-"; 7<p?E7
httpConnection.setRequestProperty("RANGE",sProperty); Fl;!'1
Utility.log(sProperty); FST}:*dOe5
nH -1,#`g
&nX,)"
InputStream input = httpConnection.getInputStream(); =as\Tp#d
//logResponseHead(httpConnection); t?404
)o>1=Y`[z
4[^lE?+
byte[] b = new byte[1024]; >W7IWhm3
int nRead; J0a#QvX!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "Ir.1FN
{ Mh;rhQ
nStartPos += fileAccessI.write(b,0,nRead); >HlQ+bl$xw
//if(nThreadID == 1) v'W`\MKY)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^tY$pPA
} K`% I!Br
@!zT+W&
wc6v:,&
Utility.log("Thread " + nThreadID + " is over!"); &6}] v:
bDownOver = true; z~+gche>
//nPos = fileAccessI.write (b,0,nRead); Qpaan
} Y\1XKAfB
catch(Exception e){e.printStackTrace ();} ` "JslpN
} J~URv)g
} KQ\d$fX
TDnbX_xC<
P2^((c
//打印回应的头信息 $bv l.c
public void logResponseHead(HttpURLConnection con) ~PAbtY9}U
{ <{yQNXf[
for(int i=1;;i++) 4hh=z>$|l)
{ O)i]K`jk
String header=con.getHeaderFieldKey(i); b/dyH
if(header!=null) 06peo d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z/>0P* F
Utility.log(header+" : "+con.getHeaderField(header)); *)H&n>"e
else '#faNVPABh
break; 7gY^aMW
} d[Lr`=L;
} ,)JSXo
7TN94@kCF
t4E=
public void splitterStop() N2_9V~!
{ h]z>H~.<*
bStop = true; Jxy94y*
} b 7%O[
l-mf~{
<DjFMTCN
} OK"B`*
P Zc{wbjp&
\d)~.2$G*
/* j/9Uf|z-_
**FileAccess.java u/8urxpy
*//文件访问(定位，写) lC&B4zec
package NetFox; kW=GFj)L
import java.io.*; r+WY7'c
>S:>_&I`I
|,wp@)e6h
public class FileAccessI implements Serializable{ vHz]-Q-|9
m+m,0Ey5H
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8Qg,UX
RandomAccessFile oSavedFile; )|@ H#kv?
long nPos; [# '38
0u'qu2mV
B "z`X!\
public FileAccessI() throws IOException T]fu[yRVvg
{ Cp@' k;(
this("",0); ?]#U~M<'
} )KLsa`RV:
%4Thb\T
bqt*d)$
public FileAccessI(String sName,long nPos) throws IOException tsA+B&R_]
{ VYZkHjj)2i
oSavedFile = new RandomAccessFile(sName,"rw"); :z!N_]t
this.nPos = nPos; 4,|A\dXE
oSavedFile.seek(nPos); Evn=3Tw
} :uD*Q/
#*<*|AwoW|
]E+deM
public synchronized int write(byte[] b,int nStart,int nLen) $rh{f<
{ NZyGC Vh@
int n = -1; }(r%'(.6
try{ 6O>GVJbw
oSavedFile.write(b,nStart,nLen); fiq4|!^h
n = nLen; ]OZk+DU:
} %;E/{gO
catch(IOException e) TFWx(}1
{ p(F}[bP
e.printStackTrace (); lo*)%fy
} <?UIux
KnC;j-j
/@<Pn&Rq
return n; z3 lZ3
} L]goHs
Qw ukhD7
\V#2K><
} |nN{XjNfP5
rR4_=S<Mi:
y0d a8sd)
/* E2s lpo
**SiteInfoBean.java D9;2w7v
*/ DJ)z~W2I*
package NetFox; !c+Nf2I7S
cVt MCgx
}jQxwi)
public class SiteInfoBean { 1N_Gk&
R7o3X,-iwn
* ?a-m\
private String sSiteURL; //Site's URL XA~Cc<v
private String sFilePath; //Saved File's Path .X;zEyd
private String sFileName; //Saved File's Name mZ^z%+Ca|
private int nSplitter; //Count of Splited Downloading File \G?GX
7|IOn5
E*ug.nxy
public SiteInfoBean() fAu^eS%>7
{//nSplitter的缺省值为5 ^ 2"r't
//default value of nSplitter is 5 nVF?.c
this("","","",5); Dk!;s8}*c
} +mQMzZZTZ
cY|?iEVs)
pcd*K)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ymdZ#I-
{ $r`^8/Mq3
sSiteURL= sURL; JC~L!)f
sFilePath = sPath; IcM99'P(
sFileName = sName; L7*,v5
this.nSplitter = nSpiltter; R^PPgE6!$
gAA2S5th
8,Jjv*
} Une,Y4{u
T[}A7a6g_
X|}yp|
public String getSSiteURL() /STFXR1@.u
{ b]'Uv8fbF
return sSiteURL; }Km+5'G'U
} cnQ;6LtFTz
c/Fy1Lv\
l,n0=Ew
public void setSSiteURL(String value) jP?YV
{ T5; zgr
sSiteURL = value; U~j:b{
} 4+ BWHV
R36BvW0X
:}\w2W E[
public String getSFilePath() ?v4-<ewD
{ ~s@PP'!
return sFilePath; -a``
} eSNwAExm
}Ut*Y*
mRe BS
public void setSFilePath(String value) x;&01@m.
{ #-xsAKi
sFilePath = value; DQ'=$z
} '->%b
_g|zDi^
WaY_{)x
public String getSFileName() yrp5\k*{y
{ h0}=C_.^
return sFileName; F)ak5
} {:U zW\5l)
O)y|G%O
J<g$hk
public void setSFileName(String value) !^{0vFWE
{ #wXq'yi
sFileName = value; woCmpCN*I
} >K }j}M%
\qx$h!<
kvWP[! j?)
public int getNSplitter() k3F*D
{ ~*OQRl6F
return nSplitter; r5U[jwP
} L*a:j
[{]/9E/&
5K_KZL-
public void setNSplitter(int nCount) P9Yee!*H
{ CH!>RRF
nSplitter = nCount; S$ u`)BG):
} Wpgp YcPS
} bC_qoI<
K(&I8vAp
KIY/nu
/* tPv3nh
**Utility.java en6Kdqe
*/ 5Lmhip
package NetFox; pKeK6K\8
-&N^S?
F1m 1%
public class Utility { $AGW8"
n}KF)W=
&I8Q'
public Utility() :<t%Sf
{ cK()_RB#
EL*OeyU1l
Z~&$s
} 5)tDgm
ZDMv8BP7
//线程睡眠 q1rBSlzN
public static void sleep(int nSecond) DRp h?V\
{ Mnj\t3:
try{ 9|kc$+(+6
Thread.sleep(nSecond); V*xo3hU
} 0:NCIsIm<
catch(Exception e) RKIBFP8.
{ &hTe-Es
e.printStackTrace (); .[%^~q7
} UH8q:jOi
} S511}KPbm/
K]~! =j)v
//日志 WJ%4IaT
public static void log(String sMsg) ,]A|z ~q
{ 5Q)hl.<{o7
System.err.println(sMsg); @1+gY4g
} _/FpmnaY
I&2)@Zw
}XOTK^YA
public static void log(int sMsg) C)x>/Qr~
{ 4Ss4jUj
System.err.println(sMsg); ^("23mhfJ
} 7T\LYDT
} gu~JB
{RG4m{#9
v'0WE
/* 9'$\GN{0
**TestMethod.java 0m3:!#\
*/ mP!=&u fcU
package NetFox; LS"_-4I}
s5`CV$bz
@ Sq =q=S
public class TestMethod { prIPPeMdz
a ~
!?AgAsSmc
public TestMethod() V-1H(wRu
{ ///xx/weblogic60b2_win.exe 5|nT5oS
try{ 4q9+a7@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Yz%AKp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ":qhO0
SiteFileFetch fileFetch = new SiteFileFetch(bean); "3&bh>#qY
fileFetch.start(); UyFvj4SU
} g2Hz[C(
catch(Exception e){e.printStackTrace ();} A7`+XqG
2F}D?]A
ec8iZ8h8
} M0jC:*D`"
=d+~l
)9pRT dT
public static void main(String[] args) oouhP1py,
{ G+_Q7-o&d6
new TestMethod(); pB;U*lt
} 1{fu
} [Re.sX}$Y
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