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)); |<%!9Z
} KKeMi@N
for(int i=0;i<nEndPos.length-1;i++) %!|w(Povq
{ >1y6DC
nEndPos = nStartPos[i+1]; ?ukw6T
} 1Pf(.&/9_
nEndPos[nEndPos.length-1] = nFileLength; S_}`'Z )
} Cj5mM[:s
} Lu.zc='\
*kr/,_K
>rG>Bz^Pu
//启动子线程 LQ0/oYmNc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yNu_>!Cp5
for(int i=0;i<nStartPos.length;i++) ?^|`A}q#
{ 18g_v"6o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hl*vS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Cu"Cpt[
nStartPos,nEndPos,i); .nV2n@SR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >J"INI
fileSplitterFetch.start(); DA=!AK>
} ,'#TdLe
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7y=>Wa?T[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3"fDFR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A_9WSXR
nEndPos = " + nFileLength); qTO6I5u
// fileSplitterFetch[nPos.length-1].start(); Z\0Rw>#
xm'9n?
@sXFu[!U
//等待子线程结束 _vQ52H,
//int count = 0; XTol|a=
//是否结束while循环 UK`A:N2[
boolean breakWhile = false; L"_XWno
#h5:b`fDF
A|A~$v("R
while(!bStop) HDVimoOq
{ bMH~vR
write_nPos(); {@Wv@H+4
Utility.sleep(500); rTD+7 )E
breakWhile = true; ?vXgHDs^T
wjarQog5Y
=u~nLL
for(int i=0;i<nStartPos.length;i++) Lx"GBEkt7
{ |Q?h"5i"(
if(!fileSplitterFetch.bDownOver) _\!]MV
{ ;m/e|_4;y
breakWhile = false; nF3}wCe)
break; r924!zdbR
} %L|fTndKH
} HR>Y?B{
if(breakWhile) l.YE@EL
break; fHt\KP
=C %)(|
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//count++; <'y<8gpM
//if(count>4) ;p`1Y<d-O
// siteStop(); AGhenDNV
} *X5)9dq
Spm 0`
6F\ 6,E
System.err.println("文件下载结束！"); %"RJi?
} ]lWqV
catch(Exception e){e.printStackTrace ();} X+vKY
} I8H3*DE
LG}{ibB
kR]P/4r
//获得文件长度 q8 v iC|
public long getFileSize() rxCzPF
{ iOL$|Z(
int nFileLength = -1; l{By]S
try{ RQ+,7Ir
URL url = new URL(siteInfoBean.getSSiteURL()); !V|{(>+<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (m]l -Re
httpConnection.setRequestProperty("User-Agent","NetFox"); ["Zvwes#7
G|i0n
~id6^#&>
int responseCode=httpConnection.getResponseCode(); zAgX{$/Fg
if(responseCode>=400) Z0gtliJ@
{ Y;'<u\^M"
processErrorCode(responseCode); D 0Xl`0"'
return -2; //-2 represent access is error ( eV,f
} *&U~Io"U
[6GYYu\
>hunV'vu'
String sHeader; %9-^,og
D(b01EQ;d
fk*(8@u>
for(int i=1;;i++) -L2.cN_
{ !Ko2yn}6l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3(YvqPp&
//Utility.log(in.readLine()); Hv6h7-
sHeader=httpConnection.getHeaderFieldKey(i); )f?I{
if(sHeader!=null) !gh8 Qs
{ i_qY=*a?y
if(sHeader.equals("Content-Length")) \w9}O2lL
{ E@VQxB7+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (s8b?Ol/
break; zJQh~)
} OB>Hiy
} S-t#d7'B
else AD?zBg Zu
break; 41 F;X{Br
} N8A)lYT]_u
} .?}M(mL
catch(IOException e){e.printStackTrace ();} c*KE3:
catch(Exception e){e.printStackTrace ();} }#z1>y!#
?v^NimcZ
M/S~"iD
Utility.log(nFileLength); 4o>y9
\gA!)q.;
~^wSwd[
return nFileLength; NuZ2,<~9
} Dfs^W{YA
=VC18yA
=Rd`"]Mnfb
//保存下载信息（文件指针位置） U`v2Yw3E
private void write_nPos() "@ >6<(Ki
{ +pd,gG?dW
try{ X[tt'5
output = new DataOutputStream(new FileOutputStream(tmpFile)); W(q3m;n
output.writeInt(nStartPos.length); '-wmY?ZFxy
for(int i=0;i<nStartPos.length;i++) reu[rZ&
{ %;`Kd}CO
// output.writeLong(nPos); j~v`q5X
output.writeLong(fileSplitterFetch.nStartPos); <J509j
output.writeLong(fileSplitterFetch.nEndPos); j>8DaEfwx
} ;|Cdq
output.close(); b.*LmSX#
} c^}G=Z1@
catch(IOException e){e.printStackTrace ();} yan^\)HZ
catch(Exception e){e.printStackTrace ();} \Qml~?$@lH
} tYA@J["^
?Y"%BS+pt
161P%sGx2
//读取保存的下载信息（文件指针位置） 0O3O^ 0
private void read_nPos() $;v! ,>
{ ?(ORk|)kU
try{ -K|1w'E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ly[yn{
int nCount = input.readInt(); r]9-~1T
nStartPos = new long[nCount]; WNR]GI
nEndPos = new long[nCount]; vF\>;pcT
for(int i=0;i<nStartPos.length;i++) O_QDjxj^rZ
{ z'l$;9(y
nStartPos = input.readLong(); t:wBh'K~R8
nEndPos = input.readLong(); $dM_uSt
} i{$-[*WHiV
input.close(); Vh-8pFt
} K0w}l" )A
catch(IOException e){e.printStackTrace ();} =O}I{dNKZV
catch(Exception e){e.printStackTrace ();} S:1[CNL;
} CPB{eQeDuv
Es>' N3A z
1$Hou
private void processErrorCode(int nErrorCode) Q4XlYgIV2A
{ oh5'Isb$
System.err.println("Error Code : " + nErrorCode); 4DL;Y
} }c G)$E
yaz6?,)
|>Q>d8|k
//停止文件下载 ~n=DI/AJ@-
public void siteStop() 2u.0AG
{ ^ITF*
bStop = true; $J1`.Q>)4
for(int i=0;i<nStartPos.length;i++) rHKO13WF
fileSplitterFetch.splitterStop(); d(IJ-qJN
bi8_5I[
qU26i"GHp
} !Z_+H<fi+I
} e!6yxL*[@[
//负责部分文件的抓取 ebA95v`Vms
**FileSplitterFetch.java =$OGHc
*/ suEK;Bk9
package NetFox; bM?gAY]mB8
7O1MC 8{
8N&'n
import java.io.*; oAO{4xP
import java.net.*; XG|N$~N+2
(d4btcg
V]|X ,G
public class FileSplitterFetch extends Thread { [8T{=+k
tz;3
cWW?@_
String sURL; //File URL UZ<K'H,q
long nStartPos; //File Snippet Start Position ;JxL>K(
long nEndPos; //File Snippet End Position q,Gymh;
int nThreadID; //Thread's ID puPI^6y%
boolean bDownOver = false; //Downing is over b8K]>yDAh
boolean bStop = false; //Stop identical ^J]&($-
FileAccessI fileAccessI = null; //File Access interface *RkUF!)(
k`5I"-e
WW:G( \`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^ ]9K>}
{ ///Lg{ie
this.sURL = sURL; 96w2qgc2
this.nStartPos = nStart; bK:U:vpYm
this.nEndPos = nEnd; ((ebSu2-?$
nThreadID = id; <vcU5 .K.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 FKO2UY#&7
} `D;*.zrA
pGD@R=8
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public void run() VAiJL
{ M5{#!d}^D
while(nStartPos < nEndPos && !bStop) "pkdZ
{ a``|sn9
]g-%7g|
{+9RJmZg
try{ i"&FW&W
URL url = new URL(sURL); MtkU]XKGT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &nIu^,.
httpConnection.setRequestProperty("User-Agent","NetFox"); F85_Lz4
String sProperty = "bytes="+nStartPos+"-"; uZ6krI
httpConnection.setRequestProperty("RANGE",sProperty); C8K2F5c5
Utility.log(sProperty); _mSefPl
1(DiV#epG
GK/Po51
InputStream input = httpConnection.getInputStream(); ZVgfrvZP
//logResponseHead(httpConnection); T-N>w;P
JP8}+
Et3I(X3
byte[] b = new byte[1024]; d?7?tL2
int nRead; `XxnQng
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @v2<T1UC
{ { b$"SIg1E
nStartPos += fileAccessI.write(b,0,nRead); 3en9TB
//if(nThreadID == 1) mG S4W;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z>W:+W"o
} %>FtA)
>._d2.Q'
Uxjc&o
Utility.log("Thread " + nThreadID + " is over!"); -leX|U}k
bDownOver = true; Q]9$dr=Kk0
//nPos = fileAccessI.write (b,0,nRead); r *K
} !JA;0[;l=
catch(Exception e){e.printStackTrace ();} Cu7{>"
} 529b. |
} Na91K4r#
.I:rb~&
>[ B.y
//打印回应的头信息 s#Dj>Fej
public void logResponseHead(HttpURLConnection con) {<yapBMw
{ ZR!8hw8
for(int i=1;;i++) `=Ip>7T&
{ )'kpO>_G
String header=con.getHeaderFieldKey(i); _V$'nz#>e
if(header!=null) 6nTM~]5.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -,")GA+[7
Utility.log(header+" : "+con.getHeaderField(header)); j*>J1M3E
else [1rQ'FBB^1
break; =muQ7l:(
} {JfQQP&FV
} IHTimT?
p{Q6g>?[
c~hH 7/v
public void splitterStop() M|blg!j;
{ |O(>{GH
bStop = true; t9`{^<LH
} /1EAj
qA[lL(
gBqDx|G
} ?L }>9$"
rDFrreQP
"VZ1LVI
/* y`RzcXblIZ
**FileAccess.java dgP eH8_
*//文件访问(定位，写) ;g0s1nz
package NetFox; rMwa6ZO'm;
import java.io.*; jf3Zy:*K
t2,II\Kl
.{ v$;g
public class FileAccessI implements Serializable{ SXw r$)4_
k3bQ32()
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r<0E[~
RandomAccessFile oSavedFile; *duG/?>P
long nPos; dBI-y6R
Y|R=^ =d\
_9>,9aL
public FileAccessI() throws IOException Hf('BagBL
{ SRfh{u
this("",0); m]?Z_*1
} 9\"\7S/Z
btg= # u
b d 1^
public FileAccessI(String sName,long nPos) throws IOException }{F)Ren
{ Pk;w.)kT
oSavedFile = new RandomAccessFile(sName,"rw"); CFFb>d
this.nPos = nPos; `ArUoYbB
oSavedFile.seek(nPos); %* 0GEfl/
} v\@qMaPY
5[;[Te9=S
e_b,{l#
public synchronized int write(byte[] b,int nStart,int nLen) Ii+3yE@c
{ Bj7*2}
int n = -1; XH%pV
try{ /[TOy2/;%b
oSavedFile.write(b,nStart,nLen); UIEvwQ
n = nLen; c~U0&V_`j
} GQt5GOt
catch(IOException e) 0$|VkMq(
{ "-f]d~P>
e.printStackTrace (); k^}[+IFJ
} -f|/#1
SNqSp.>-U"
1NP
return n; _\>y[e["p
} 2mEqfy
C@Wzg
I7vP*YE 7F
} 5.^pD9[mT
0#NMNZ
bkJ bnW=
/* .6gx|V+
**SiteInfoBean.java ,t 2CQ
*/ uUfw"*D
package NetFox; Ij(dgY
XEiVs\) G
uL)MbM]
public class SiteInfoBean { im*sSz 0 (
7=fM}sk
"\*)KH`C
private String sSiteURL; //Site's URL a>GA=r
private String sFilePath; //Saved File's Path 3.YH7rN
private String sFileName; //Saved File's Name | +;ZC y
private int nSplitter; //Count of Splited Downloading File DG;u_6;JR
{APfSD_4
O ?T~>|
public SiteInfoBean() Gxd/t#;
{//nSplitter的缺省值为5 `&NFl'l1C
//default value of nSplitter is 5 v.W!
this("","","",5); "5eD >!
} p>)1Z<D"a
=+X*$'<J
;,-)Z|W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |Kd6.Mx
{ @ fMlbJq
sSiteURL= sURL; vE9"1M
sFilePath = sPath; dFg&|Lp
sFileName = sName; {b-C,J
this.nSplitter = nSpiltter; 6Y[&1c8
9-n]_AF`0
DSs/D1mj&
} <vl(a*4a
#xmiUN,|
^(&2
public String getSSiteURL() ^RnQX#+
{ Y<;C>Rs
return sSiteURL; ]/!*^;cY(
} Q+f|.0r
!}c D e12
@16y%]Q-E#
public void setSSiteURL(String value) Jha*BaD~N
{ U+VJiz<!
sSiteURL = value; <@`K^g;W
} ~6#mVP5sU)
ZS:[ZehF
S*}GW-)oA
public String getSFilePath() =3,<(F5Y[
{ nxN("$'cq
return sFilePath; pjO
} 5 n4/}s
07^.Z[(pCt
mV]~}7*Y;
public void setSFilePath(String value) l&Q@+xb>
{ gs2qLb
sFilePath = value; NZ`6iK-V_
} {;bec%pq0
8;=?F>]xn
W=2.0QmW
public String getSFileName() bY`Chb.
{ |\B\IPs{%'
return sFileName; L\Oxyi<{
} ' Sd&I:?
h%:wIkZ/
a:|]F|
public void setSFileName(String value) :8n?G
{ .aZB?MW
sFileName = value; :xq^T
} Iy5W/QK6
~i^,Z&X:
pnz@;+f
public int getNSplitter() DvEII'-h
{ Wm8BhO
return nSplitter; 3sBWtz
} q&ed4{H<
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fR.raI4et
public void setNSplitter(int nCount) nb5%a
{ a[^dK-
nSplitter = nCount; F`Vp
} Zo-Au
} zh !/24p9
JmF`5
K~L"A]+
/* @TKQ_7BcB
**Utility.java 7({.kD6
*/ $o\Uq
package NetFox; p*P0<01Z
P\c0Q;){h"
(I`<;
public class Utility { hy"p8j7_
etW-gbr
/C<} :R
public Utility() a(o[ bH.|;
{ iEFS>kL8e
cNN_KA
jM@@N.
} AMgvk`<f
;c~DBJg'|
//线程睡眠 F7x< V=4{
public static void sleep(int nSecond) p|Fhh\,*`X
{ G`!;RX
try{ A&'HlI%J
Thread.sleep(nSecond); F0NNS!WP7^
} (aCl*vV1
catch(Exception e) J! eVw\6
{ nfvs"B;
e.printStackTrace (); Z.LF5ur
} S67T:ARS
} FHH2
zGFW?|o<
//日志 [TV"mA
public static void log(String sMsg) }\ui}\
{ 5Q72.4HH
System.err.println(sMsg); =TI|uD6T
} .uagD[${
d>4e9M"
13{"sY:PT#
public static void log(int sMsg) {&(bKQ
{ ]O&A:Us
System.err.println(sMsg); +ACV,GG
} ;v+CQx
} OEGAwP?F
>Q\H1|?
ELNA-ZKp
/* WU,72g=
**TestMethod.java Zr2QeLQC(
*/ FkECY
package NetFox; B 9]sSx
{78*SR
{K0T%.G
public class TestMethod { uJp}9B60_
g9"_BG
<F.Ol/'h
public TestMethod() 7#|NQ=yd
{ ///xx/weblogic60b2_win.exe Sdt2D
try{ &FvNz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lB\j>.c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?y45#Tk]
SiteFileFetch fileFetch = new SiteFileFetch(bean); LveqG
fileFetch.start(); +Vf|YLbhJ
} S(-=I!.G{
catch(Exception e){e.printStackTrace ();} E 0pF; P5
CX'E+
s9GPDfZ
} TAC\2*bWje
@%cJjZ5y
"RX?"pB
public static void main(String[] args) {}^ELw
{ LA@}{hU
new TestMethod(); FZ2-e
} hJ4.:
} <,hBoHZSL
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