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)); 8cG?p
} @j^R+F
for(int i=0;i<nEndPos.length-1;i++) Z1eT>6|]r
{ rZKfb}ANQ
nEndPos = nStartPos[i+1]; wAKHD*M)
} f`n4'dG
nEndPos[nEndPos.length-1] = nFileLength; Z^_qXerjP
} !?nbB2,
} hyH[`wiq
ysz =Xw
_K o#36.S
//启动子线程 V4+|D2
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .\ ;'>qy
for(int i=0;i<nStartPos.length;i++) ECOJ .^
{ h^SWb91"G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `gX|q3K\s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D5,]E`jwu
nStartPos,nEndPos,i); oZa'cZNs
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'OsZD?W{
fileSplitterFetch.start(); 8M99cx*K
} wM+1/[7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4.!1odKp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); } ?j5V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B?! L~J@p
nEndPos = " + nFileLength); 6Ijt2c'A}
// fileSplitterFetch[nPos.length-1].start(); t3@+idEb
ISGw}#}]?
J!2Z9<q5
//等待子线程结束 ^ Oh
//int count = 0; k7^hcth
//是否结束while循环 *%Rmdyn
boolean breakWhile = false; 4j#y?^s
(xHmucmwp
J].Oxch&y
while(!bStop) d=D-s
{ k,:W]KD
write_nPos(); =Kd'(ct
Utility.sleep(500); +<a\0FsD
breakWhile = true; jE*{^+n
7*l$i/!
z`zz8hK.
for(int i=0;i<nStartPos.length;i++) geme_
{ eFG/!b<17
if(!fileSplitterFetch.bDownOver) 3`bQ0-D;
{ ;P91'B~t
breakWhile = false; {7o3wxsS
break; 6KMO*v
} ,<v0(
} wZ(1\ M(
if(breakWhile) fz(YP=@ZnP
break; #EH=tJgO|J
BU:;;iV8
=W~7fs
//count++; ON,[!pc
//if(count>4) i#'K7XM2
// siteStop(); qYK^S4L
} MgXZN{
Tn&_ >R
#`VAw ) eV
System.err.println("文件下载结束！"); ;z'&$#pA
} 8ymdg\I+L
catch(Exception e){e.printStackTrace ();} BJjic%V
} ,"EaZ/Bl/
2lTt
}J#HIE\RG
//获得文件长度 *ERV\/
public long getFileSize() "^#O7.oVi+
{ zjmoIE
int nFileLength = -1; P~j#8cH7
try{ Bgxk>Y
URL url = new URL(siteInfoBean.getSSiteURL()); S2$66xr#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {KG}m'lx
httpConnection.setRequestProperty("User-Agent","NetFox"); +F)EGB%LXs
GW AT0
Ui'v' $
int responseCode=httpConnection.getResponseCode(); t]h_w7!U
if(responseCode>=400) 2R\K!e
{ 5i[O\@]5
processErrorCode(responseCode); &W45.2
return -2; //-2 represent access is error p:~#(/GWf
} ~P\4 N
%Psg53N
~su>RolaX
String sHeader; ?(9*@
=t,oj6P~
hIV9.{J
for(int i=1;;i++) [U&k"s?
{ _}F&^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y!b"Cj
//Utility.log(in.readLine()); @NM0ILE
sHeader=httpConnection.getHeaderFieldKey(i); B ~v6_x
if(sHeader!=null) "yu{b]AU
{ A[l )>:
if(sHeader.equals("Content-Length")) "9;
{ 2+&;jgBP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x{pj`'J)
break; TAYh#T=S
} [j6]!p]S$
} V D#q\
else sl$6Zv-l%0
break; ^(q .f=I!a
} QD-\'Bp/X
} Vh0cac|X
catch(IOException e){e.printStackTrace ();} 7m#EqF$P
catch(Exception e){e.printStackTrace ();} E-WpsNJ)X
lf=G
EB3/o7)L
Utility.log(nFileLength); f&vMv.
!KI^Z1dP(
Fg`<uW]TFZ
return nFileLength; p*<Jg l
} /we]i1-9
-53c0g@X
=X'[r
//保存下载信息（文件指针位置） ~i1 jh:,
private void write_nPos() #ft9ms#N
{ Qb {[xmc
try{ G8}owszT
output = new DataOutputStream(new FileOutputStream(tmpFile)); - +a,Ej
output.writeInt(nStartPos.length); iQO4IT
for(int i=0;i<nStartPos.length;i++) LVUA"'6V
{ `+Nv=vk
// output.writeLong(nPos); vd%AV(]<LJ
output.writeLong(fileSplitterFetch.nStartPos); "nz\YQdg
output.writeLong(fileSplitterFetch.nEndPos); 2*sTU
} &<><4MQ
output.close(); M[qhy.
} ?b7ttlX{
catch(IOException e){e.printStackTrace ();} {J"]tx9 ]
catch(Exception e){e.printStackTrace ();} 2D:/.9= 8v
} _OGv2r
y{M7kYWtHV
r1HG$^
//读取保存的下载信息（文件指针位置） Kb]}p
private void read_nPos() ,~3rY,y-
{ ^P,Pj z
try{ S/oD`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XVNJK-B
int nCount = input.readInt(); 3/gR}\=
nStartPos = new long[nCount]; +X#6dv$
nEndPos = new long[nCount]; m^FKE:
for(int i=0;i<nStartPos.length;i++) ?n#$y@U
{ ?$`kT..j,u
nStartPos = input.readLong(); \dQc!)&C9
nEndPos = input.readLong(); Yz;7g8HI
} 3D6&0xTq
input.close(); B*:I-5
} 0:Bpvl5
catch(IOException e){e.printStackTrace ();} %<^^ Mw
catch(Exception e){e.printStackTrace ();} bGwOhd<.
} |[~S&
zHKP$k8
C[fefV9g2
private void processErrorCode(int nErrorCode) ^U?Ac=
{ g(zeOS]q}
System.err.println("Error Code : " + nErrorCode); yf*'=q
} RR=WD-l
-\p&18K#
Fah6 &a
//停止文件下载 V]Te_ >E;w
public void siteStop() J#Q>dC7
{ :^W}$7$T
bStop = true; <cZ/_+H%C
for(int i=0;i<nStartPos.length;i++) >&\.{ aj
fileSplitterFetch.splitterStop(); }bRn&)e
ITl>HlS
p9jC-&:
} (Q*x"G#4>
} V0D&bN*
//负责部分文件的抓取 8Vz!zYl
**FileSplitterFetch.java @_t=0Rc
*/ FI:H/e5[
package NetFox; Zrwd
jvv=
wdt2T8`I/
import java.io.*; ?#a&eW
import java.net.*; Jqzw94
2ih}?%H8
Syseiw
public class FileSplitterFetch extends Thread { _8r'R
q{V e%8$"
/t`|3Mw
String sURL; //File URL e<uf)K=(C
long nStartPos; //File Snippet Start Position 0,-]O=
long nEndPos; //File Snippet End Position X9PbU1o;
int nThreadID; //Thread's ID @-K[@e/uwy
boolean bDownOver = false; //Downing is over ;07$G+['
boolean bStop = false; //Stop identical Xl1%c7r.1
FileAccessI fileAccessI = null; //File Access interface kIa16m
9:g A0Z
_1RvK? ;.{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4<tbZP3/6)
{ B#hvw'}
this.sURL = sURL; :LB*l5\
this.nStartPos = nStart; ~)#E?:h5
this.nEndPos = nEnd; LK4NNZf7
nThreadID = id; ">!pos`<C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 uO]|YF
} vn*K\,
J|hVD
`3jwjy|5
public void run() I++ Le%w
{ .Y2Hd$rs
while(nStartPos < nEndPos && !bStop) NRG06M
{ q_^yma
P7T'.|d
f99"~)B|
try{ ez9F!1
URL url = new URL(sURL); Py#EjF12
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #-Mr3
httpConnection.setRequestProperty("User-Agent","NetFox"); Wm"q8-<<
String sProperty = "bytes="+nStartPos+"-"; 8.jf6
httpConnection.setRequestProperty("RANGE",sProperty); [(g2u@
Utility.log(sProperty); 1`|Z8Jpocj
zOA~<fhT
J~J+CGT~2
InputStream input = httpConnection.getInputStream(); P<Z` 8a[
//logResponseHead(httpConnection); &ZMQ]'&
|wJdp,q R
$bp$[fX(e
byte[] b = new byte[1024]; sqpo5~
int nRead; ";`jS&"=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \IC^z
{ &Jb$YKt
nStartPos += fileAccessI.write(b,0,nRead); IhK SwT
//if(nThreadID == 1) h}'Hst
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q=%W-
} $bKXP(
E@otV6Wk[@
{S+?n[1r\
Utility.log("Thread " + nThreadID + " is over!"); D=vw0Q_3Y3
bDownOver = true; #b&tNZ4!_
//nPos = fileAccessI.write (b,0,nRead); pam9wfP
} |15!D
catch(Exception e){e.printStackTrace ();} iku*\,6W
} Gjq7@F'
} 2o9B >f&g
'_7rooU9
'Q=)-
//打印回应的头信息 8EkzSe
public void logResponseHead(HttpURLConnection con) P@GU2[1
{ l]D$QT3
for(int i=1;;i++) 'bLP#TAzf
{ ( ./MFf
String header=con.getHeaderFieldKey(i); f?^-JZ
if(header!=null) dZIbajs'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r?Mf3U^G
Utility.log(header+" : "+con.getHeaderField(header)); \z2y?"\?
else I+twI&GS
break; LHx ")H?,
} 2!}F+^8'P
} 3 eF c
@=AQr4&
YCStX)r
public void splitterStop() GPGPteC
{ H-&27?s^
bStop = true; T<>B5G~%
} *7Y#G8 s
"8uNa
p*g)-/mA
} un!v1g9O
li?@BHEf
+\%]<YO
/* ox<&T|
**FileAccess.java 2G-"HOG
*//文件访问(定位，写) VHqoa>U,*
package NetFox; 7neJV
import java.io.*; ct|0zl~
{*n<A{$[ m
4qE4 i:b
public class FileAccessI implements Serializable{ $ S3b<]B
Ap?,y?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y)lr+~84f
RandomAccessFile oSavedFile; ><IWF#kUA
long nPos; G Wa6FX:/
ipMSMk7gx
/d6Rdl`w
public FileAccessI() throws IOException mE{QTZS
{ ;u(*&vRqr^
this("",0); T?[;ej:
} vOCaru?~h
s&o9LdL
I:oEt
public FileAccessI(String sName,long nPos) throws IOException Ebj0 {ZL
{ W3Ee3
oSavedFile = new RandomAccessFile(sName,"rw"); S9$,.aq
this.nPos = nPos; 3)CIqN
oSavedFile.seek(nPos); aynaV
} i" u|119
i Pr(X
VfJ{);
public synchronized int write(byte[] b,int nStart,int nLen) A9SL|9Q
{ oI`Mn3N
int n = -1; 1;kMbl]
try{ 8;"%x|iBoL
oSavedFile.write(b,nStart,nLen); UMNNAX
n = nLen; |Fze9kZO
} 3}phg
catch(IOException e) ns5Dydo{T
{ .eVX/6,
e.printStackTrace (); gn/]1NNfR
} O^./)#!#
6W3oIt
]Oo!>iTQi
return n; :epB:r
} p`7d9MV^
]<YS7.pT
mYJ8O$
} uMGy-c
I*o6Bn |D
H'k~;
/* Jpp-3i.F#
**SiteInfoBean.java '>1M~B
*/ _(gkYJ+MK
package NetFox; # SCLU9-
&,PA+#
Z>3~n
public class SiteInfoBean { bxxLAWQ(
\6APU7S
B[YyA
private String sSiteURL; //Site's URL 5M'cOJ
private String sFilePath; //Saved File's Path 9cN@y<_I
private String sFileName; //Saved File's Name $4ZV(j]
private int nSplitter; //Count of Splited Downloading File *Uy>F[%@
,3}+t6O"
a9^})By&
public SiteInfoBean() kzUj)
{//nSplitter的缺省值为5 Oz_CEMcy
//default value of nSplitter is 5 3;}YW^oXq
this("","","",5); RaTNA W)v>
} NW0se DL
3"0QW4A
b0h\l#6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KgD$P(J:[
{ H*0g*(
sSiteURL= sURL; jZidT9[g
sFilePath = sPath; @%u}|iF|
sFileName = sName; B[8RBTsA
this.nSplitter = nSpiltter; AriV4 +
_O87[F1
]x8Y]wAU&{
} +U,t*U4,
] X]!xvN@
B&59c*K
public String getSSiteURL() Z \ @9*
{ 0]DX KI
return sSiteURL; x2I|iA=
} LHOt(5VY
kn3GgdU
6-?/kY6
public void setSSiteURL(String value) n@bkZ/G
{ +J|LfXgB
sSiteURL = value; tZ@&di:-F
} !(Y|Vm'
MMaS
p\'X%R
public String getSFilePath() ~PF,[$?4n
{ k"BM1-f
return sFilePath; Edh9=sxL
} u\xrC\Ka
G5 )"%G.
u|ihUE!h
public void setSFilePath(String value) p'@z}T?F
{ Gk58VODo
sFilePath = value; loq2+(
} &2@Rc?!6_P
!m_y@~pV#u
wp~KrUlR
public String getSFileName() T72Z<h|<
{ Avljrds+7
return sFileName; u5U^}<}y}
} d@Bd*iI<
\Z%_dT}
}Sh@.3*
public void setSFileName(String value) sKiy1Ww
{ 1#>uqUxah
sFileName = value; 8BS Nm
} w[QC
Zmk 9C@
<Z]j89wzDZ
public int getNSplitter() E){ODyk
{ (]fbCH:
return nSplitter; 8rU| Oh
} UY.o,I>s
|P9)*~\5
@frV:%
public void setNSplitter(int nCount) Opy{i#>
{ 5PpS/I:on
nSplitter = nCount; MM@&QaK
} rO1N@kd/
} DYZk1
65+2+p
XL1x8IB
/* vHPsHy7y
**Utility.java $Zrc-tkV
*/ 3ox|Mz<aZX
package NetFox; /b4>0DXT5
uAk>VPuuZ
1F2(MKOo!
public class Utility { e5n"(s"G*[
vsq |m5
?FZ) LZM
public Utility() C6tfFS3bq
{ vhU $GG8
&y3;`A7,
_(@Vf=t
} xWWVU}fd1
Ci3 b(KR
//线程睡眠 [RDY(}P%
public static void sleep(int nSecond) sa"!ckh
{ `7V'A
try{ 7<5=fYbr
Thread.sleep(nSecond); r8_MIGM'
} P$/Y9o
catch(Exception e) (.$e@k=
{ cm>+f^4?n
e.printStackTrace (); Qz<i{r-z
} jq/CXYv
} JWxSN9.X
ae+*gkPv8
//日志 Oj7).U0;#
public static void log(String sMsg) 5*y6{7FLp
{ Qer}eg`R
System.err.println(sMsg); GRgpy
} v@:m8Y(t
5lE9UoG[Q
pf&SIG
public static void log(int sMsg) xwijCFI*
{ "(;t`,F
System.err.println(sMsg); ;Z&w"oSJ
} j|r$!gV
} )EsFy6K:
"!o|^nN,
S"Ag7i
/* n1y*`5!
**TestMethod.java 1W>0
*/ R+=Xr<`%U|
package NetFox; l27J
A^7}:[s20
}pT>dbZ
public class TestMethod { HwBJUr91]
#\O?|bN'q
t)l^$j!h@
public TestMethod() @p9YHLxLjQ
{ ///xx/weblogic60b2_win.exe %wmbFj}
try{ G>+iisb%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q{Gf@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r 4+%9)
SiteFileFetch fileFetch = new SiteFileFetch(bean); J/A UOInh
fileFetch.start(); BbNl:`
} 2,'%G\QT
catch(Exception e){e.printStackTrace ();} (0S;eM&
{mB &xz:b
J<ZG&m362p
} 24d{ol)
{pk&dB _Bu
$7&t`E)qY
public static void main(String[] args) l| QQ
{ E"t79dD
new TestMethod(); >L88`
} 8FT@TUFb
} A@ 4Oq
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