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)); A~y VYC6l
} R7K
for(int i=0;i<nEndPos.length-1;i++) [b`$\o'-
{ q6)N*?
nEndPos = nStartPos[i+1]; NG-`ag`s
} YRa4W.&Yn
nEndPos[nEndPos.length-1] = nFileLength; [t}):}~F|
} 2]Fu 1
} 6Kht:WE
O]_={%
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//启动子线程 sMJ#<w}Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g\J)= ,ju,
for(int i=0;i<nStartPos.length;i++) )+B=z}:Nfz
{ GMb!Q0I8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W:B}u\)C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), = o+7xom
nStartPos,nEndPos,i); @^HwrwRA
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RK3.-
fileSplitterFetch.start(); Oy'0I,
} _W+Q3Jx-(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $~o3}&az
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^Ezcy?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R<j<.h
nEndPos = " + nFileLength); N l|^o{#
// fileSplitterFetch[nPos.length-1].start(); z|%Bh
o}!&y?mp
e[p^p!a
//等待子线程结束 W9jNUZVXE#
//int count = 0; :~r#LRgc
//是否结束while循环 Ph"iX'J
boolean breakWhile = false; 3:O+GQ*
W:>J864!
mS7E_A8
while(!bStop) wy\o*P9mG)
{ ]-rczl|o
write_nPos(); EFNdiv$wF
Utility.sleep(500); Fj3^ #ly
breakWhile = true; VS%@)sI|Z
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r&/D~g\"|[
for(int i=0;i<nStartPos.length;i++) Si[eAAd' :
{ $l43>e{E
if(!fileSplitterFetch.bDownOver) v['AB4
{ 1l~.R#WG&
breakWhile = false; PIpWa$b
break; nO:HB.&@
} CH#kvR2
} ZK!4>OuH`
if(breakWhile) / (.'*biQ
break; /J8o_EV
q4zSS #]A
nYgx9Q"<om
//count++; gm}C\q9
//if(count>4) FBbm4NB
// siteStop(); &BTfDsxAK
} B~BUWWMfp
.yG8B:7N2
{;;eOxOP|
System.err.println("文件下载结束！"); \hu':@}
} 8}J(c=4Gk
catch(Exception e){e.printStackTrace ();} i!y\WaCp
} d^_itC;-,
f0g6g!&gf
=X<)5IS3
//获得文件长度 xz="|HD);
public long getFileSize() BMe72
{ myffYK,
int nFileLength = -1; T+3k$G[e/
try{ 3me<~u
URL url = new URL(siteInfoBean.getSSiteURL()); $<14JEU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XuA0.b%
httpConnection.setRequestProperty("User-Agent","NetFox"); e ^-3etx
ul}4p{ m[
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int responseCode=httpConnection.getResponseCode(); O} (E(v
if(responseCode>=400) |#!eMJ&0
{ ./2Z?,
processErrorCode(responseCode); ]+FX$+H/A0
return -2; //-2 represent access is error #fJwC7 4
} N.k+AQb
S54gqc1S]
rR3m'[
String sHeader; EF0Pt
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6{lG1\o
for(int i=1;;i++) '=-s1c@^
{ b^+Fs
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7BVXBw
//Utility.log(in.readLine()); aKaR
sHeader=httpConnection.getHeaderFieldKey(i); 1+VY><=n
if(sHeader!=null) ]gjr+GV
{ *c!;^Qyp&
if(sHeader.equals("Content-Length")) aGdpecv
{ Qs~d_;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6zELe.tq
break; AfuXu@UZ_/
} nmTm(?yE
} Q|6Ls$'$
else =I %g;YK
break; z0=Rp0_W
} rwasH,+
} Sa(yjF1
catch(IOException e){e.printStackTrace ();} z%++\.g_
catch(Exception e){e.printStackTrace ();} X!7czt
Ompi~
"m wl-=
Utility.log(nFileLength); >SY2LmV'a
hwEZj`9
(R9QBZP5
return nFileLength; m+;B!46
} (rau8
&Bj,.dD/a
TXZ(mj?
//保存下载信息（文件指针位置） 49iR8w?k
private void write_nPos() *1 n;p)K
{ VyB\]EBu
try{ -G(3Y2
output = new DataOutputStream(new FileOutputStream(tmpFile)); l{M;PaJ`}
output.writeInt(nStartPos.length); )Ix-5084
for(int i=0;i<nStartPos.length;i++) @>qx:jx(-S
{ D|u^8\'.
// output.writeLong(nPos); UIC\CP d
output.writeLong(fileSplitterFetch.nStartPos); +,ZUTG
output.writeLong(fileSplitterFetch.nEndPos); H5 p}Le
} y|&.v<
output.close(); ]}UeuF\
} yEMX`
catch(IOException e){e.printStackTrace ();} !D.= 'V
catch(Exception e){e.printStackTrace ();} i}v}K'`
} 7.w*+Z>z
*u:;:W&5y
;:#?~%7>
//读取保存的下载信息（文件指针位置） 1(#*'xR
private void read_nPos() b#?ai3E
{ =F",D=
try{ +0oyt?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c4!c_a2pS
int nCount = input.readInt(); z'vdC
nStartPos = new long[nCount]; Tx|SAa=V
nEndPos = new long[nCount]; v^y}lT
for(int i=0;i<nStartPos.length;i++) ,(;p(#F>
{ 7eaA]y~H
nStartPos = input.readLong(); yDu yMt#
nEndPos = input.readLong(); > {'5>6u
} #;qFPj- v
input.close(); doxdRYKL
} 7 K;'7
catch(IOException e){e.printStackTrace ();} P3,Z5|)
catch(Exception e){e.printStackTrace ();} X~IRpzC
} t z +
J_y<0zF**
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private void processErrorCode(int nErrorCode) -z>Z0viA
{ _rWM]
System.err.println("Error Code : " + nErrorCode); c5T~0'n
} {UV<=R,E
Lic{'w&
<Y}"D Yt
//停止文件下载 Ti9:'I
public void siteStop() ZTgAZ5_cz
{ ;*<{*6;=?
bStop = true; MHpL$g=5_
for(int i=0;i<nStartPos.length;i++) %~~z96(
fileSplitterFetch.splitterStop(); n6}E4Eno
l1+w2rd1
rC1qGzg\a
} zezofW]a
} Y1yvI
//负责部分文件的抓取 $~w@0Yl
**FileSplitterFetch.java 34+)-\xt:
*/ yP<:iCY
package NetFox; G>_42Rp
(d5vH)+A
N>cp>&jV
import java.io.*; -6em*$k^
import java.net.*; Xd19GP!
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:e0R7sj
public class FileSplitterFetch extends Thread { G]m[S-
*1ID`o
;S{Ld1;
String sURL; //File URL O>b&-U"R
long nStartPos; //File Snippet Start Position m"?'hR2
long nEndPos; //File Snippet End Position \U<F\i
int nThreadID; //Thread's ID k Nf!j
boolean bDownOver = false; //Downing is over U:pLnNp`
boolean bStop = false; //Stop identical fRv S@
FileAccessI fileAccessI = null; //File Access interface :) Fp B"
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b Q9"GO<X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Us@ {w`T
{ Gg3?2h"d
this.sURL = sURL; ~'Qpf 8)
this.nStartPos = nStart; ^%4( %68
this.nEndPos = nEnd; mNBpb}
nThreadID = id; x jP" 'yU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "$,}|T?Y`
} NBbY## w0
@tjZvRtZ
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public void run() )z*$`?)k
{ 7Y @=x#
while(nStartPos < nEndPos && !bStop) 9rf|r 3
{ )@lo ';\
@$b+~X)7
um_M}t{
try{ !w;A=
URL url = new URL(sURL); v#<+n{B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ./BP+\)lO
httpConnection.setRequestProperty("User-Agent","NetFox"); *~t$k56
String sProperty = "bytes="+nStartPos+"-"; +hKPOFa'
httpConnection.setRequestProperty("RANGE",sProperty); [ ;3EzZL
Utility.log(sProperty); ru6HnLhL
t+4%,n f_1
gS(: c.
InputStream input = httpConnection.getInputStream(); 9q0,K" x)
//logResponseHead(httpConnection); -SC2Zgi)A
1 [~|
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byte[] b = new byte[1024]; QF.wtMGF&
int nRead; Z+"E*
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )8N)Z~h
{ ^B"_b?b
nStartPos += fileAccessI.write(b,0,nRead); tWX+\ |
//if(nThreadID == 1) 2AdHj&XE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )l!&i?h%
} xUYN\Pc-
+G=C~X
8L9S^ '
Utility.log("Thread " + nThreadID + " is over!"); D^R! |K/
bDownOver = true; HNHhMi`w
//nPos = fileAccessI.write (b,0,nRead); t&Y^W <
} V@+<,tjq
catch(Exception e){e.printStackTrace ();} H@&"M%
} >*Qk~kv<%
} BS<>gA R;/
E<m"en&v
Dk{nOvZu<
//打印回应的头信息 Vo9)KxR
public void logResponseHead(HttpURLConnection con) abk:_
{ @l6dJ
for(int i=1;;i++) C7*Yg$`{
{ B=RKi\K6a
String header=con.getHeaderFieldKey(i); G3?a~n^b
if(header!=null) s)7`r6w
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )dN,b(w9
Utility.log(header+" : "+con.getHeaderField(header)); 8KdcLN@
else d7-F&!sQ
break; aid)q&AcQ
} 5A=xFj{
} !E>3N:
"F.J>QBd
O9 Au =
public void splitterStop() ^MWW,`
{ &B5Rzz-'
bStop = true; CYic_rF$
} \?mU$,voI
NNpa69U
G?/8&%8
} 1.OXkgh
T.Y4L
TX5/{cHd
/* zm^p7&ak$
**FileAccess.java N@`9 ~JS
*//文件访问(定位，写) v_F?x!
package NetFox; {~p %\
import java.io.*; x?k |i}Q
bA9dbe
P*^UU\x'4I
public class FileAccessI implements Serializable{ GMp'KEQQ
H(ftOd.y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %KVRiX
RandomAccessFile oSavedFile; 5>k~yaju/
long nPos; <HX-qNA?
[(^''*7r+T
HBkQ`T
public FileAccessI() throws IOException GISI8W^
{ 6 VJj(9%
this("",0); 21J82M
} l[j0(T
K0!#l Br
`];[T=
public FileAccessI(String sName,long nPos) throws IOException 9(Xch2tpO!
{ Fl(ZKpSZU
oSavedFile = new RandomAccessFile(sName,"rw"); 5TW<1'u
this.nPos = nPos; $G([#N<
oSavedFile.seek(nPos); gmH0-W)=
} HE.Dl7{
Qz90 mb
!{=%l+^.
public synchronized int write(byte[] b,int nStart,int nLen) rlh6\Fa
{ g<jK^\eW
int n = -1; -Y,Ibq
try{ 4'eVFu+62
oSavedFile.write(b,nStart,nLen); leqSS}KU+
n = nLen; j W]c9u
} ^\t">NJ^
catch(IOException e) ]V7hl#VO
{ *>H'@gS
e.printStackTrace (); ~bQ:gArk
} 8k}CR)3@C
\A"a>e
9jFDBy+
return n; L.&Vi"M <@
} Gi_X+os
~x#-#nuh"
t-{OP?cE1
} jS)-COk
)n61IqrW
c^UM(bW
/* fO|u(e
**SiteInfoBean.java XSIO0ep
*/ Ppn ZlGQ6
package NetFox; E)SOcM)
d`*vJ#$>2
ApB'O;5
public class SiteInfoBean { m`6`a|Twp$
5w%9b
e/l?|+m 6
private String sSiteURL; //Site's URL 9GOyVKUv
private String sFilePath; //Saved File's Path _C\ d^a(
private String sFileName; //Saved File's Name o[*ih\d
private int nSplitter; //Count of Splited Downloading File eh=bClk
nr%^:u
,$*klod
public SiteInfoBean() o{,(`o.1O
{//nSplitter的缺省值为5 AYtcN4\/
//default value of nSplitter is 5 U}5KAi 9Z
this("","","",5); |-?b)yuAz
} c'4 \F9
~0t'+.
jDR\#cGrZ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 35\0g&
{ :~(^b;yhZ
sSiteURL= sURL; rJ*WxOoS{
sFilePath = sPath; C!A_PQ2y
sFileName = sName; pfIvBU?
this.nSplitter = nSpiltter; SQRz8,sqkw
+4RaN`I
<AXYqH7%A
} !S<~(Ujyw
x@x@0k`A2
sVf7g?
public String getSSiteURL() \p|!=H@
{ VdrF=V&] O
return sSiteURL; Sa(rl^qZ2
} 7tnzgtal
`fHiY.-
:"^$7
public void setSSiteURL(String value) HuClO
{ |1x,_uyQ%
sSiteURL = value; @TT[H*,
} Gj0NN:
11'Tt!
6<GWDO
public String getSFilePath() a_x6 v*
{ 9dv~WtH>5
return sFilePath; 247>+:7z
} M>#S z
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)HHzvGsL)
public void setSFilePath(String value) S]{Z_|h*j
{ :@L5=2Z+
sFilePath = value; Gj?q+-d!(5
} ]].21
O2B$c\pw
r3)t5P*_
public String getSFileName() %dQX d]
{ w,$17+]3
return sFileName; zAIC5fvu
} S^.=j oI
YEj U3^@
LdL\B0^l
public void setSFileName(String value) mLqm83
{ O@$i
sFileName = value; C\[UAxZ3X
} &kE|~i:=,9
C?J%^?v
hkxZ=l
public int getNSplitter() /J:j'6
{ XDQ1gg`
return nSplitter; YKk%;U*
} ]QQ"7_+
NI)nf;C
F'!}$oT"
public void setNSplitter(int nCount) 03y<'n
{ .?TVBbc%5
nSplitter = nCount; \k8_ZJw
} 5{[0Clb)
} dWSH\wm+
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IU}`5+:m
/* :|TBsd|/x
**Utility.java $+j)
*/ 3{=4q
package NetFox; MJoC*8QxM
~]Jfg$'
fQh!1R
public class Utility { ,#{aAx|]
<o O_wS@:
&iivSc;#
public Utility() !k^\`jMzw
{ 'UKB pm/
Nt?B(.G
b7/4~_s
} ZhU2z*qN#
(A_9;uL^_
//线程睡眠 >E#4mm
public static void sleep(int nSecond) uNjy&I:
{ Q]C1m<x
try{ ijfT!W
Thread.sleep(nSecond); mvxvX!t
} I nk76-
catch(Exception e) R !HL+
{ `7`iCYiTy
e.printStackTrace (); 191)JWfa
} .'M]cN~
} a>6p])Wh
\uH;ng|m
//日志 Rh|&{Tf
public static void log(String sMsg) ek<U2C_u#
{ z!tHn#
System.err.println(sMsg); t<-Iiq+tL
} $= gv
d>f5Tl\E
~rD* Y&#.
public static void log(int sMsg) I`7[0jA~
{ }j x{Cw
System.err.println(sMsg); ESAh(A)8
} y!j1xnzki
} \BA_PyS?W+
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EW)]75o{QF
/* LdcP0G\"VG
**TestMethod.java ,fbO}
*/ xYbF76B
package NetFox; HDYoM
G7u7x?E:B`
YAD9'h]d\
public class TestMethod { G8@%)$A
F-m1GG0s
y9 "!ys
public TestMethod() zPn8>J<.0Q
{ ///xx/weblogic60b2_win.exe zT@vji%Y
try{ mYZH]oo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'yl`0,3wV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SRMy#j-
SiteFileFetch fileFetch = new SiteFileFetch(bean); $%/Zm*H
fileFetch.start(); 1mf_1spB
} fE >FT9c
catch(Exception e){e.printStackTrace ();} &A>J>b
-1[ri8t;nV
=d9%ce
} ]0o78(/w2
T ^uBMDYe
*<KY^;
public static void main(String[] args) Li}yK[\]
{ nG2RBeJV
new TestMethod(); *%8dW
} FBe1f1 sm
} v+Hu=RZE
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