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)); F'>yBDm*OM
} %).I&)i
for(int i=0;i<nEndPos.length-1;i++) w0@XJH:P
{ #g@4c3um|
nEndPos = nStartPos[i+1]; ~3Pp}eO~V
} <,it<$f#
nEndPos[nEndPos.length-1] = nFileLength; >Ik%_:CC`
} cUP1Uolvn
} o\ce|Dzt
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7p\&D?
//启动子线程 U[Sh){4j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3?<A]"X.
for(int i=0;i<nStartPos.length;i++) }6pr.-J
{ h4itXJy52B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5(\/ b<#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'AWWdz
nStartPos,nEndPos,i); ]b>XN8y.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g18zo~LZ
fileSplitterFetch.start(); Nxl#]
} g~,iWoY
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =bP<cC=3b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,SIGfd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |:4W5>sfg
nEndPos = " + nFileLength); (pM&eow}
// fileSplitterFetch[nPos.length-1].start(); ^fsC]9NS
op2Zf?Bx{+
kG9aHWw
//等待子线程结束 x!W5'DO
//int count = 0; 0FH.=
//是否结束while循环 js;YSg{m
boolean breakWhile = false; Avyer/{
K$GQc"
|H,WFw1%}
while(!bStop) zsd<0^ p\{
{ ZybfqBTD&c
write_nPos(); v5e*R8/
Utility.sleep(500); TG8U=9qt
breakWhile = true; of7p~{3H
6&6dd_K(
? p[Rv
for(int i=0;i<nStartPos.length;i++) S76MY&Vx23
{ YMNLn9
if(!fileSplitterFetch.bDownOver) -Vb5d!(
{ D-t!{LA
breakWhile = false; 8 l= EL7
break; yn@wce
} @`nG&U
} ^x/D8M
if(breakWhile) })kx#_o]'d
break; MK! @ND
C8qSoO4Z
MQcIH2
//count++; p/u
//if(count>4) ek/zQM@%
// siteStop(); lb*;Z7fx<'
} \+/ciPzA-
thX4-'i
90Sras>F
System.err.println("文件下载结束！"); bQ 0Ab"+D
} sK9RViqF\
catch(Exception e){e.printStackTrace ();} FqGMHM\J
} )MTf
yP} |8x
_ MB/p
//获得文件长度 ~,)D n
public long getFileSize() x./"SQ=R+
{ l O*
int nFileLength = -1; /B 3\e3
try{ -vc$I=b;
URL url = new URL(siteInfoBean.getSSiteURL()); =\oW{?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9C Ki$L
httpConnection.setRequestProperty("User-Agent","NetFox"); ,JbP~2M~%
m:~y:.
c68y\
int responseCode=httpConnection.getResponseCode(); |/8!PKm
if(responseCode>=400) Btr>ek
{ cD!E.2[
processErrorCode(responseCode); c05-1
return -2; //-2 represent access is error u0)9IZxc
} vr?u=_%Z
./.aLTh
P|lDW|}D@
String sHeader; O8v9tGZoh
IZ^:wIKo{
]B~(yh
for(int i=1;;i++) BG.8 q4[
{ qe e_wx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cH:&S=>h
//Utility.log(in.readLine()); kz("LI]
sHeader=httpConnection.getHeaderFieldKey(i); 'L9hM.+
if(sHeader!=null) +eKLwM
{ +R;LHRS%
if(sHeader.equals("Content-Length")) Sd.Km a
{ (~5]1S}F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); umAO&S.+M
break; 8cMX=P
} <s|.2~
} ci:|x =
else |)0Ta9~
break; 2 w! 0$
} 3,*A VcQA
} PQYJnx}
catch(IOException e){e.printStackTrace ();} WD[jEWMV7D
catch(Exception e){e.printStackTrace ();} QuI!`/N)z
|f1^&97=+
ZWjje6
Utility.log(nFileLength); SdMLO6-
>\J<`
7i02M~*uS
return nFileLength; '^7UcgugB
} '"LaaTTs
&m9= q|;m
BXxJra/V
//保存下载信息（文件指针位置） vo)W ziHh
private void write_nPos() (Nd)$Oq[4
{ K)[\IJJM
try{ "s_S!;w@
output = new DataOutputStream(new FileOutputStream(tmpFile)); <HS{A$]
output.writeInt(nStartPos.length); =`N0
for(int i=0;i<nStartPos.length;i++) mF4OLG3L0
{ )$a6l8
// output.writeLong(nPos); EKN<KnU%
output.writeLong(fileSplitterFetch.nStartPos); K&gE4;>
output.writeLong(fileSplitterFetch.nEndPos); T/%Y_.NtU
} ,VUOsNN4\
output.close(); ux6)K= ]
} MU `!sb*
catch(IOException e){e.printStackTrace ();} xdaq` ^Bbt
catch(Exception e){e.printStackTrace ();} d|~'#:y@
} @;{ZnRv14
x{So
'0_W<lGB
//读取保存的下载信息（文件指针位置） $rbr&TJ
private void read_nPos() T?jN/}qg
{ Eg2jexl
try{ )S`Yl;oL
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Hv:~)h$
int nCount = input.readInt(); ^u0y<kItX
nStartPos = new long[nCount]; 42,dHYdt
nEndPos = new long[nCount]; u%1JdEWZd
for(int i=0;i<nStartPos.length;i++) Yb[)ETf^
{ pa?AKj]
nStartPos = input.readLong(); 87)/dHc
nEndPos = input.readLong(); 'iwTvkf{
} Z?9G2<i
input.close(); \)aFYDq#\
} 3KkJQ5a
catch(IOException e){e.printStackTrace ();} R `ob;>[Q
catch(Exception e){e.printStackTrace ();} /S^>06{-+
} ^HTvw~]5
|m*l/@1
>lek@euqw
private void processErrorCode(int nErrorCode) $DnJ/hg;qD
{ m@L>6;*
System.err.println("Error Code : " + nErrorCode); *g:Dg I 2
} WHLTJ]OB
d#ab"&$bv
)/OIzbA3#
//停止文件下载 [{&OcEf
public void siteStop() *] >R
{ 8)Vl2z
bStop = true; qAlX#]
for(int i=0;i<nStartPos.length;i++) 3Y +;8ld
fileSplitterFetch.splitterStop(); tF<&R&=
YT)1_>*\
Su +<mW
} NQiu>Sg
} zNn
//负责部分文件的抓取 ?LvU7
**FileSplitterFetch.java [{vX*q 3B
*/ =W"T=p*j
package NetFox; 30sA\TZ
AxO.adQE%
qzZ;{>_f
import java.io.*; oGbh*
import java.net.*; "dYT>w
BPOT!-
<@4V G
public class FileSplitterFetch extends Thread { ).Iifu|ks
%Br1b6 V
{`>pigo
String sURL; //File URL /%{CJ0Y
long nStartPos; //File Snippet Start Position 0dD.xuor
long nEndPos; //File Snippet End Position hX-^h2eV
int nThreadID; //Thread's ID rCA0c8
boolean bDownOver = false; //Downing is over ICG:4n(,
boolean bStop = false; //Stop identical pk;S"cnk
FileAccessI fileAccessI = null; //File Access interface GQjU="+
m>!o Yy_
:r:x|[3.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C&EA@U5X^
{ AnZy oa
this.sURL = sURL; `J7@G]X;2
this.nStartPos = nStart; KO[T&#y'
this.nEndPos = nEnd; R.GDCGAL
nThreadID = id; N];K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p"*xyex
} 8`I,KkWg
*W 04$N
mWLiXKnb
public void run() M3JV^{O/DV
{ `bLJwJ7
while(nStartPos < nEndPos && !bStop) l Yj$3
{ AmCymT3P*e
2@N-#x'
Dj0D.}`~
try{ 0juP"v$C>
URL url = new URL(sURL); QV#HN"F/K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VjeF3pmBa
httpConnection.setRequestProperty("User-Agent","NetFox"); 3?!c<^"e
String sProperty = "bytes="+nStartPos+"-"; ]&='E.f
httpConnection.setRequestProperty("RANGE",sProperty); 5pff}Ru`
Utility.log(sProperty); jF#Dc[*
d@Wze[M?0
eG.s|0`
InputStream input = httpConnection.getInputStream(); "412w^5[T
//logResponseHead(httpConnection); Tg=P*HY6
Tx'anP
4:s,e<Tc4v
byte[] b = new byte[1024]; l @E {K|
int nRead; fP\*5|7%R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -BwZ
{ ,~Lx7 5{
nStartPos += fileAccessI.write(b,0,nRead); (H]NL
//if(nThreadID == 1) A9GSeW<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :j32 :/u
} 'Awd:Aed5
4P7r\hs
X&M04
Utility.log("Thread " + nThreadID + " is over!"); =66'33l2
bDownOver = true; n6c+Okj
//nPos = fileAccessI.write (b,0,nRead); Z:,`hW*A6
} }+)q/]%
catch(Exception e){e.printStackTrace ();} h=kC3ot\
} 4`+R |"4
} =&: |a$C
uj)fah?Wg
idjk uB(6
//打印回应的头信息 $L'[_J
public void logResponseHead(HttpURLConnection con) F$YT4414
{ #3FsK
for(int i=1;;i++) sP>-k7K.
{ ~svea>Fmr
String header=con.getHeaderFieldKey(i); ?ihRt+eR~
if(header!=null) fUq #mkq}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h5v=h>c
Utility.log(header+" : "+con.getHeaderField(header)); fM(~>(q&
else "|E'E"_1
break; @F|pKf:M+
} -AB0uMot
} m`tX&K#-
2=VFUR 8
r\C"Fx^
public void splitterStop() eyn-bw
{ Fgi;%
bStop = true; !R[~Z7b6
} @"aqnj>+
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3/,}&SX
} `2M*?.vk
}:]CXrdg>
EO/41O
/* #9HX"<5
**FileAccess.java M>{*PHze0
*//文件访问(定位，写) K d{o/R
package NetFox; NjO_Y t
import java.io.*; 7gRR/&ZK
P9jSLM
zu,Yuq
public class FileAccessI implements Serializable{ l4& l)4Rx
.OlPVMFt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1%";|
RandomAccessFile oSavedFile; )E^Pn|H
long nPos; p?4,YV|#
`r %lB
q7I(x_y /
public FileAccessI() throws IOException [<wpH0lNoy
{ qu;$I'Ul%
this("",0); \0FwxsL
} #[Rs&$vQm
jcRe),
R_ )PbFw
public FileAccessI(String sName,long nPos) throws IOException +DE;aGQ.z?
{ 1aPFpo!
oSavedFile = new RandomAccessFile(sName,"rw"); 4rpry@1
this.nPos = nPos; n8i: /ypB
oSavedFile.seek(nPos); tY#Zl 54~{
} XI,=W
hd`jf97*
dt/-0~U
public synchronized int write(byte[] b,int nStart,int nLen) i\x@s>@x}
{ l9&L$,=
int n = -1; 4P#4RB
try{ uII! ?
oSavedFile.write(b,nStart,nLen); ^4et; F%
n = nLen; PO,zP9
} zT93Sb
catch(IOException e) ;Nd'GA+1;(
{ d<w]>T5VW
e.printStackTrace (); ^~dC&!D
} e{^^u$C1.e
(i1p6
pwV~[+SS_
return n; KDj/S-S
} Z/ L%?zH
;J:*r0
TV`sqKW
} mE&SAm5#d
+Eel|)Z*Q
G2b"R{i/,
/* i(V
**SiteInfoBean.java !/X>k{
*/ \S{ihS@J
package NetFox; {Z178sik
uuL(BUGt-
a%?v/Ku
public class SiteInfoBean { q d:"LS
4JXJ0T ar
z0F55<i
private String sSiteURL; //Site's URL nswhYSX
private String sFilePath; //Saved File's Path Bj\Us$cZ
private String sFileName; //Saved File's Name b`f6(6
private int nSplitter; //Count of Splited Downloading File 2-@t,T
;Zn&Nc7
7p>T6jK)
public SiteInfoBean() D[4%CQ1m
{//nSplitter的缺省值为5 c5pK%I}O
//default value of nSplitter is 5 KcW 5
this("","","",5); Dj6^|R$z&
} ]cMZ7V^
==trl#kQ%%
*z0Rf;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %/ :&L+q
{ ^ (J%)&_\3
sSiteURL= sURL; _,I~1"
sFilePath = sPath; o@C|*TXN
sFileName = sName; u#Bj#y!
this.nSplitter = nSpiltter; g4;|uK;
f lt'~fe
4ywtE}mp
} dP#7ev]'
gADqIPu]
ad=7FhnIa3
public String getSSiteURL() =`Ky N/
{ =FdFLrx~l
return sSiteURL; 17w{hK4o8O
} 1&Ma`M('
UWdqcOr
UF@.
public void setSSiteURL(String value) :`0,f?cE
{ A5[kYD,_
sSiteURL = value; A{\DzUV9,
} $"#M:V@
L3j ~Ooo
?DnQU"_$
public String getSFilePath() >xH?`I7;f
{ D7c+/H@PF
return sFilePath; 7 Rc/<,X
} -x?|[ +%
RusiCo!r
Oo ^AE
public void setSFilePath(String value) dkg+_V!
{ 5bol)Z9BO
sFilePath = value; `}8)P#
} PAVlZ}kj
#;m^DX QZn
49Y:}<Yd
public String getSFileName() psS^
{ 'z+Pa^)v
return sFileName; UA#=K+2
} ]HRHF'4
")fgQ3XZ
7'`nTF-@v
public void setSFileName(String value) 472'P
{ TETfRnm
sFileName = value; P+3 ]g{2w
} ]0{,P !
#!rH}A>n+
.0|_J|{
public int getNSplitter() q"-Vh,8h
{ "{jVsih0
return nSplitter; `"$9L[>
} A~LTi
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s2nZW pIy
public void setNSplitter(int nCount) CKDg3p';
{ q"LT8nD\
nSplitter = nCount; gX* &RsF
} g~OG~g@
} q?f-h<yRQ
@*$"6!3s5
J/[PA[Rf
/* UG<<.1JL
**Utility.java t4-0mNBZt$
*/ 2$gFiZ
package NetFox; pFwe&_u]
?W&ajH_T
6p14BruV
public class Utility { \/r]Ra
i2\CDYP
(. ,{x)H
public Utility() `oE.$~'
{ fl*49-d
Ba n^wX
N/E=-&E8
} ]oC7{OoX
'qidorT>N
//线程睡眠 f{'NO`G
public static void sleep(int nSecond) JJP!9<
{ ?;go5f+X
try{ h0VeXUM;.
Thread.sleep(nSecond); sWgzHj(c
} 1mx;b)4t
catch(Exception e) @9MrTP
{ EFs\zWF
e.printStackTrace (); a & 6-QVk
} j!a&l
} dp:5iuS
{|Fn<&G
//日志 V#+J4
public static void log(String sMsg) K*"Fpx{M
{ L!2Ef4,wAz
System.err.println(sMsg); 0#F<JsO|u
} "04:1J`
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x2g=%K=
public static void log(int sMsg) NbUibxJ
{ eZ(o_
System.err.println(sMsg); kwFo*1 {
} |%=c<z+8
} m9aP]I3g]\
.r-kH&)"GU
v/3Vsd
/* U[!wu]HMF
**TestMethod.java Zg >!5{T
*/ g^:7mG6C
package NetFox; Zor Q2>
!(N,tZ
!]!9 $6n
public class TestMethod { 4rNuAK`2
HOVzpj
]@sLX ek
public TestMethod() &>hln<a>
{ ///xx/weblogic60b2_win.exe `mKK1x
try{ 8#a2 kR<b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ybgw#jv=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m pM,&7}
SiteFileFetch fileFetch = new SiteFileFetch(bean); NW?h~2
fileFetch.start(); XN'<H(G
} Fi#b0S
catch(Exception e){e.printStackTrace ();} 6x! q
q.p.y0
,j\UZ
} UC"_#!3
{s[,CUL0
h/#s\>)T
public static void main(String[] args) P Z+Rz1x
{ *lp{,
new TestMethod(); ~g;lVj,N'
} ]N1gzHaS
} u[coWaPsZ
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