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)); ;tKL/eI
} GWP"i77y0s
for(int i=0;i<nEndPos.length-1;i++) kZn!]TseN
{ (EohxLl!p
nEndPos = nStartPos[i+1]; vTB*J,6.
} q F}5mUcZ4
nEndPos[nEndPos.length-1] = nFileLength; H) (K
} pX*mX]
} d2(eX\56Z
DJ<e=F!
kXG+zsT
//启动子线程 `SIJszqc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AM Rj N;
for(int i=0;i<nStartPos.length;i++) 6^ KDc
{ I>P</TE7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &[3!Lk`.0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EA8(_}
nStartPos,nEndPos,i); Jl^oDW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8zpK;+
fileSplitterFetch.start(); 'TbA^U[
} )6AOP-M.9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6J=~*&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fA+M/}=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", A4&e#
nEndPos = " + nFileLength); z?7s'2w&{
// fileSplitterFetch[nPos.length-1].start(); Rx'7tff%I
{fX4
[s7I.rdGzz
//等待子线程结束 K1eoZ8=!
//int count = 0; wOa_"
//是否结束while循环 ,*C^ixNE
boolean breakWhile = false; M{(Y|3W
tB1Qr**
cBm3|@7
while(!bStop) }!.7QpA$
{ -(1e!5_-@
write_nPos(); tv;3~Y0i
Utility.sleep(500); -7+Fb^"L
breakWhile = true; X^@d@xU4v
}B]FHpi
pXQ&2s$
for(int i=0;i<nStartPos.length;i++) ^Jkj/n'
{ {'vvE3iZ
if(!fileSplitterFetch.bDownOver) xt`znNN
{ Ezml LFp.
breakWhile = false; Ni0lj:
break; mKn[>M1
} ' u0{h
} e`_3= kI
if(breakWhile) oVsl,V
break; K}$PIW
{+`ep\.$&
S[ 2`7'XV
//count++; j#~4JGZt
//if(count>4) wTTQIo60
// siteStop(); q?t>!1c
} nl?|X2?C
''WX
w'qV~rN~tc
System.err.println("文件下载结束！"); m<076O4|`
} )<Yy.Z_:DC
catch(Exception e){e.printStackTrace ();} $23R%8j
} LBM:>d5
=+"XV8Fi,
4H " *.l
//获得文件长度 :Z+(H+lyZ
public long getFileSize() _p~ `nQ=7
{ %R_8`4IQ
int nFileLength = -1; o= 8yp2vG
try{ ',CcLN
URL url = new URL(siteInfoBean.getSSiteURL()); AM}OLHj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %_3{Db`R>
httpConnection.setRequestProperty("User-Agent","NetFox"); Lh. L~M1X
h7Ma`w\-
CP?\'a"Kt
int responseCode=httpConnection.getResponseCode(); m.4y=69 &
if(responseCode>=400) ()SG
{ v=L^jw
processErrorCode(responseCode); X'3F79`
return -2; //-2 represent access is error {fS/ZG"5<t
} RnTPU`
O=+C Kx@
:r~?Z6gK
String sHeader; {!EbGIh
"%Rx;xw|
P|6m%y
for(int i=1;;i++) ,Wdyg8&.
{ )^r4|WYyt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +q2l,{|?
//Utility.log(in.readLine()); <Z0Tz6/j,
sHeader=httpConnection.getHeaderFieldKey(i); fj"S|]e
if(sHeader!=null) V8N<%/A=
{ ]#J]f
if(sHeader.equals("Content-Length")) 9wAP%xh
{ */qv}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9^}GUJy?
break; }SOj3.9{c
} XCt}>/"s\h
} >o[T#U
else f^]2qoN
break; hxtu^E/
} U 26Iz
} (*M(gM{;
catch(IOException e){e.printStackTrace ();} 8,H
catch(Exception e){e.printStackTrace ();} M,6AD]
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u4Xrvfb,
Utility.log(nFileLength); ZBnf?fU
1f~DUku=
2R1W[,Ga!
return nFileLength; N,;Bl&EU
} @ojn<7W
b.t]p
G.BqT\ o'
//保存下载信息（文件指针位置） sDwSEg>#B
private void write_nPos() t;? q#!uc
{ V1Fdt+#
try{ LOOv8'%O8
output = new DataOutputStream(new FileOutputStream(tmpFile)); *=ALns?y
output.writeInt(nStartPos.length); apYf,"|9
for(int i=0;i<nStartPos.length;i++) [NuayO3
{ uH7u4f1Q
// output.writeLong(nPos); #q=?Zu^Da
output.writeLong(fileSplitterFetch.nStartPos); 0/*z]2
output.writeLong(fileSplitterFetch.nEndPos); y6Rg@L&U
} muY4:F.C(
output.close(); +tOV+6Uz
} l~\'Z2op
catch(IOException e){e.printStackTrace ();} Kj}}O2
catch(Exception e){e.printStackTrace ();} _@HMk"A
} _E?(cWC
"V^(i%E;
gjwp' GN
//读取保存的下载信息（文件指针位置） .m4K ]^m
private void read_nPos() dvUJk<;w
{ jd$lu^>I
try{ Iw48+krm>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {Ynr(J.
int nCount = input.readInt(); N7[i443a
nStartPos = new long[nCount]; J\Sewg9
nEndPos = new long[nCount]; 0/),ylCj
for(int i=0;i<nStartPos.length;i++) WJhI6lu
{ 0chBw~@*s
nStartPos = input.readLong(); d*!,McBn
nEndPos = input.readLong(); 7?F0~[eGG
} W>h[aVTO
input.close(); 6@nEcr
} 2avSsN{^
catch(IOException e){e.printStackTrace ();} ;BpuNB
catch(Exception e){e.printStackTrace ();} |)0kvf?
} uWgY+T
<oO^w&G
fv}h;?C
private void processErrorCode(int nErrorCode) <<[`;"CF
{ ]$Z aS\m
System.err.println("Error Code : " + nErrorCode); sl`\g1<{`
} )<!y_;$A
qQ^]z8g6P
obY5taOw
//停止文件下载 5B"j\TwQ
public void siteStop() l0]zZcpt
{ #N7@p}P
bStop = true; _,~/KJp
for(int i=0;i<nStartPos.length;i++) z}kD:A)a
fileSplitterFetch.splitterStop(); 3'IF?](]U
(L q^C=
"S*lI^8Z!
} @y)fR.!)1$
} Azu$F5G!n
//负责部分文件的抓取 :Oy9`vv
**FileSplitterFetch.java _g 3hXsA
*/ Un7jzAvQ
package NetFox; MdCEp1Z
1?Wk qQ
~%>ke
import java.io.*; Q]66v$
import java.net.*; PT|t6V"wd
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Pij*?qmeQ
public class FileSplitterFetch extends Thread { qm]k (/w
Y}ITA=L7
IJ[#$I+Z%
String sURL; //File URL z[[|'02{
long nStartPos; //File Snippet Start Position F"~uu9u
long nEndPos; //File Snippet End Position ?!cUAa>iH
int nThreadID; //Thread's ID f)/Yru. ;
boolean bDownOver = false; //Downing is over P**h\+M>{
boolean bStop = false; //Stop identical I6zKvP8pb
FileAccessI fileAccessI = null; //File Access interface F0])g
wwk=*X-8
5Z1b9.;.,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]qvrpI!E!
{ QGn3xM66
this.sURL = sURL; 'IKV%$k
this.nStartPos = nStart; &Z#g/Hc
this.nEndPos = nEnd; p^MV<}kk
nThreadID = id; )jm}h7,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =c[9:&5Q
} SI^!e1@M[
v[A)r]"j"M
nj]l'~Y0
public void run() r[ni{&
{ ot8UuBq
while(nStartPos < nEndPos && !bStop) ZvM~]8m
{ MV'q_{J
..)O/g.
aHuZzYQ*"j
try{ K!=Y4"5%
URL url = new URL(sURL); >kU$bh.(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _H}8eU
httpConnection.setRequestProperty("User-Agent","NetFox"); PuYAoKG
String sProperty = "bytes="+nStartPos+"-"; e5W 8YNA
httpConnection.setRequestProperty("RANGE",sProperty); W+k SL{0
Utility.log(sProperty); #R-l2OO^]
: M=0o<
U["'>&B
InputStream input = httpConnection.getInputStream(); (kCzz-_\
//logResponseHead(httpConnection); J!YB_6b
5%Hw,h
mu@He&w"
byte[] b = new byte[1024]; suiO%H^t
int nRead; ] -iMo4H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) CC"}aV5
{ 9kZ[Z ,=>
nStartPos += fileAccessI.write(b,0,nRead); ?d&l_Pa0e
//if(nThreadID == 1) <$metN~9j
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); % 8u97f W
} Ymt.>8L
lC|`DG-B
ObnQ,x(
Utility.log("Thread " + nThreadID + " is over!"); (#KSwWo{ed
bDownOver = true; (JenTL`%u
//nPos = fileAccessI.write (b,0,nRead); AWo\u!j
} UNY O P{
catch(Exception e){e.printStackTrace ();} !Pd@0n4
} "{>BP$Jz
} 8~* |muN.e
icS%])3LF
?V&#nA
//打印回应的头信息 s3<gq x-&r
public void logResponseHead(HttpURLConnection con) W2yNwB+{
{ nM#/uuRl|
for(int i=1;;i++) N(c`h
{ @@uKOFA?
String header=con.getHeaderFieldKey(i); -j& A;G
if(header!=null) .=G?Zd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); "}*5'e.*
Utility.log(header+" : "+con.getHeaderField(header)); %j $r"
else ]"q9~
break; V?t56n Y}
} HV21=W
} KJ (|skO
=2XAQiUR\
W2>VgMR [
public void splitterStop() ZQ1,6<^9i[
{ )?y${T
bStop = true; }jdMo83
} Y[sBVz'j5
+-2W{lX
'<=77yDg
} )>"|<h.2]
tW-wO[2
-8zdkm8k
/* tEuVn5
**FileAccess.java :Eb=jWA
*//文件访问(定位，写) s$g3__|Y
package NetFox; 80_}}op?8
import java.io.*; d#(ffPlq
+,c]FAx4
#M ;j*IBl*
public class FileAccessI implements Serializable{ >bRoQ8
`_"loPu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "50c<sZSB
RandomAccessFile oSavedFile; *(g0{V
long nPos; [b:0j-
3QhQpPk),
k^@dDLr"
public FileAccessI() throws IOException RoFoEp
{ .~O- <P#
this("",0); A'6-E{
} "UYlC0 S\
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u~8=ikn+T
public FileAccessI(String sName,long nPos) throws IOException zFi)R }Ot
{ l6T^e@*
oSavedFile = new RandomAccessFile(sName,"rw"); y0]"qB
this.nPos = nPos; \ gO!6
oSavedFile.seek(nPos); ZHM NG~!
} Xk] uXx:TN
!&adO,jN+=
V7<w9MM
public synchronized int write(byte[] b,int nStart,int nLen) fnJx$PD~
{ y$8S+N?>
int n = -1; GLp~SeF#
try{ w,*#z
oSavedFile.write(b,nStart,nLen); )vD:
n = nLen; i~"lcgoO
} vd9PBN
catch(IOException e) qDS~|<Y5
{ <5!)5+G
e.printStackTrace (); \_)[FC@
} M{t/B-'4
XUVBD;"f!
v%muno,
return n; .4J7 ^l
} 9fy[%M
b5)1\ANq
&q>C
} )8E[xBaO
8;d./!|'&g
3Yf~5csY
/* 7q&T2?GEN
**SiteInfoBean.java )i"52!
*/ G:!3X)b
package NetFox; s|][p|
d(YAH@
kq*IC&y
public class SiteInfoBean { weMufT
LJSx~)@
]+5Y\~I
private String sSiteURL; //Site's URL yu}T><Wst
private String sFilePath; //Saved File's Path w~~[0e+E
private String sFileName; //Saved File's Name q*<FfO=eQ
private int nSplitter; //Count of Splited Downloading File e$`;z%6y
$\#wsI(
=5O&4G`}
public SiteInfoBean() :z`L)
{//nSplitter的缺省值为5 s54AM]a{j
//default value of nSplitter is 5 bg2r
this("","","",5); vt#&YXu{A
} zmg :Z p=
Am<){&XT ]
qzWnl[3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +^q-v-
{ 8&:dzS
sSiteURL= sURL; V#+M lN
sFilePath = sPath; ZEB,Q~
sFileName = sName; &8dj*!4H
this.nSplitter = nSpiltter; B A i ^t
Ju"/#@
Tdxc%'l
} )`#SMLMy~
(g>&ov(d
* $|9e
public String getSSiteURL() a|ZJzuqo
{ v2ab84 C*
return sSiteURL; L*6>S_l[
} lvG+9e3+
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8w ]'U
public void setSSiteURL(String value) 2]5ux!Lqln
{ G%dzJpC(
sSiteURL = value; Z*Fn2I4
} _=K\E0I.m
),@m 3wQ
6u,w
public String getSFilePath() b2^O$l
{ c3)6{
return sFilePath; }-@h H(
} $e%m=@ga
RijFN.s
{ 3Qlx/6<
public void setSFilePath(String value) g6H`uO
{ @Ll^ze&HI
sFilePath = value; \98|.EG
} {A\y4D@
pYj}
gb26Y!7%
public String getSFileName() 1`9'.w+r
{ }0Fu
return sFileName; in>?kbaG+
} Np?/r}
Bam 4%G5
} DjbVYH
public void setSFileName(String value) &ZJ$V
{ wx^1lC2
sFileName = value; U3pMv|b
} T9AFL;1
8ZNwo
X1="1{8H
public int getNSplitter() `8D'r|=`Eh
{ +2m\Sv V
return nSplitter; Cdc=1,U(
} \O\veB8
R}$A>)%dx
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public void setNSplitter(int nCount) |Gt]V`4
{ 30QQnMH3
nSplitter = nCount; xKXD`-|W
} t.]e8=dE
} TYedem<$
{+ WI>3
51puR8AG>
/* *KPNWY9!W
**Utility.java )z7+%nTO
*/ \Bn$b2j!%
package NetFox; JjG>$z
= $6pL
+|Mi lwr
public class Utility { ^%x7:
jxZd =%7Q
}#E~XlX^
public Utility() %loe8yt
{ \)BDl
!qJ|`o Y
#po}Y
} 0GnbE2&
6}q# c
//线程睡眠 Jek)`D
public static void sleep(int nSecond) EYU3Pl%
{ **Q K}j[D
try{ 8yCQWDE}
Thread.sleep(nSecond); ,IG?(CK|
} 3qq6X?y*
catch(Exception e) d<v)ovQJ]
{ oBzjEv
e.printStackTrace (); d+g+{p>?
} <9Pf] G=
} 67dp)X
si|b>R&Z
//日志 |I=\+P}s
public static void log(String sMsg) 9h'klaE(
{ }t.VH:02y
System.err.println(sMsg); #zw 'H9l
} H3jb{S b
q/t~`pH3
VK?c='zg
public static void log(int sMsg) AME6Zu3Y
{ Js!V,={iX
System.err.println(sMsg); 30$Q5]T
} <@:LONe<
} BW%"]J
fm'Qifq^
( O/+.qb
/* ){XG%nC
**TestMethod.java JheF}/Bx
*/ "K-2y^Dl
package NetFox; w7X], auRC
+#R<emW
NQhlb"Ix
public class TestMethod { S t0AV.N1
[)83X\CO
e025m}%SU
public TestMethod() Gv zw=~8
{ ///xx/weblogic60b2_win.exe '}T6e1#JV
try{ =H2.1 :'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gDjs:]/YR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XxEKv=_bc
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0YVkq?1x9
fileFetch.start(); xt"GO b
} 3re|=_ Hy
catch(Exception e){e.printStackTrace ();} ZCS{D
6s|4'!
tL~?)2uEN
} JOJ?.H&su
*,d>(\&[f
#35@YMF
public static void main(String[] args) 6dq*ncNin
{ CGkCLd*s]
new TestMethod(); 9K5[a^q|My
} ce\ F~8y
} _o-D},f*e
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