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)); P\ yt!S2
} E)(`Z0
for(int i=0;i<nEndPos.length-1;i++) ] o!#]]
{ j/zD`ydj
nEndPos = nStartPos[i+1]; `_2#t1`u
} +MQvq\%tG
nEndPos[nEndPos.length-1] = nFileLength; 7f4R5c
} S}"?#=Q.%O
} -KRHcr \
DSwF }
h]Zc&&+8{
//启动子线程 $s2-O!P?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z$R2Z$f
for(int i=0;i<nStartPos.length;i++) {HqwpB\@
{ Df_W>QC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &`7~vA&c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qa![oMKc
nStartPos,nEndPos,i); =N,KVMxw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y)3(
fileSplitterFetch.start(); MDkIaz\U
} 0XlX7Sk+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i'!M<>7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .?SClTqg
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }?P~qJ|1
nEndPos = " + nFileLength); t\2myR3
// fileSplitterFetch[nPos.length-1].start(); }@'xEx
-X@;"0v
oeXNb4; 4
//等待子线程结束 >J=x";,D|~
//int count = 0; YtQKsM
//是否结束while循环 FV/xp}nz
boolean breakWhile = false; da@y*TO#i
1{ #Xa=
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while(!bStop) Q6S[sTKR
{ oB[3?e
write_nPos(); <$.KCLP
Utility.sleep(500); 4Uz:zB
breakWhile = true; #e%.z+7I
aMTY{
]P0DPea
for(int i=0;i<nStartPos.length;i++) C#r_qn
{ *f8,R"]-g
if(!fileSplitterFetch.bDownOver) C!w@Naj
{ T4 SByX9
breakWhile = false; "xdJ9Z-B
break; xsRMF&8L
} /3%]Ggwe
} /2u;w!oi.
if(breakWhile) v\Y;)/!
break; '$)Wp_
mxHNK4/
_}]o~
//count++; 4\(;}M-R{
//if(count>4) Y,D\_il_
// siteStop(); ,Ucb)8a
} HZQI|
}jd[>zk
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System.err.println("文件下载结束！"); 9szE^kHS9
} )I+1 b !U
catch(Exception e){e.printStackTrace ();} SU# S'
} |~H'V4)zXu
HXU"]s2Z
{(wV>Oc>Jw
//获得文件长度 $!I$*R&
public long getFileSize() iy tSC
{ MbnV5b:X
int nFileLength = -1; zi>f436-
try{ 62EJ# q[
URL url = new URL(siteInfoBean.getSSiteURL()); [ur/`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mC~W/KReA
httpConnection.setRequestProperty("User-Agent","NetFox"); c%~'[W04\
{yyg=AMz
C>68$wd>
int responseCode=httpConnection.getResponseCode(); Op3 IL/
if(responseCode>=400) |ry;'[*
{ U7crbj;c)d
processErrorCode(responseCode); any\}
return -2; //-2 represent access is error B_cn[?M
} W&06~dI1!
_;01/V"q6
Q,\lS
String sHeader; KvilGh10
8gC(N3/E"
MPzqw)_-v
for(int i=1;;i++) ZuS+p0H"
{ 2L<TqC{,-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]VJcV.7`
//Utility.log(in.readLine()); 4d]
sHeader=httpConnection.getHeaderFieldKey(i); 6%S>~L66
if(sHeader!=null) ^ioTd
{ uFdSD
if(sHeader.equals("Content-Length")) \((>i7C
{ ^J% w[FE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #UND'c(5
break; <2cq 0*$
} FeV=4tsy
} WgPL4D9=
else 5RLK]=
break; 5 (H; x74
} 0jq&i#yNB
} i0AC.]4e"
catch(IOException e){e.printStackTrace ();} R&xD|w8UjM
catch(Exception e){e.printStackTrace ();} Jy|Mfl%d
.j&jf^a5
2:DpnLU5
Utility.log(nFileLength); C)C;U&Qd
Kv#daAU
aRG[F*BY
return nFileLength; P`bR;2o
} L<QDC
n@mUQ6
_)Qt,$
//保存下载信息（文件指针位置） bfpW^y
private void write_nPos() xBw"RCBz^
{ *Mp<4B
try{ U'lmQrF!
output = new DataOutputStream(new FileOutputStream(tmpFile)); dfJ7Dhn
output.writeInt(nStartPos.length); Ej34^*m9k
for(int i=0;i<nStartPos.length;i++) a|s=d
{ [\.>BK
// output.writeLong(nPos); gdG: &{|x
output.writeLong(fileSplitterFetch.nStartPos); ))KsQJ"V
output.writeLong(fileSplitterFetch.nEndPos); Z#J{tXZc
} 'xi..
output.close(); '6WDs]\
} rLKDeB
catch(IOException e){e.printStackTrace ();} WG}QLcP
catch(Exception e){e.printStackTrace ();} @pS[_!EqYz
} d?{2A84S
'\_)\`a|
fglZjT
//读取保存的下载信息（文件指针位置） T8m%_U#b
private void read_nPos() ZRQPOy
{ !CMN/=
try{ |y=gp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x<3vA|o
int nCount = input.readInt(); Rw\DJJrz
nStartPos = new long[nCount]; { o;0Fx
nEndPos = new long[nCount]; ih;TQ!c+b
for(int i=0;i<nStartPos.length;i++) x)U;
{ (CV=0{]
nStartPos = input.readLong(); R;.WOies4
nEndPos = input.readLong(); -"nYCF
} G7=8*@q>:
input.close(); a #0{tZd
} h n]6he
catch(IOException e){e.printStackTrace ();} =lmh^**4
catch(Exception e){e.printStackTrace ();} kg@J.
} O71rLk;
T6,lk1S'=
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private void processErrorCode(int nErrorCode) O0l;Qi
{ He*L"VpWv
System.err.println("Error Code : " + nErrorCode); 'Hia6<m3
} a$|u!_)!h
:OZhEBL&b
U{}7:&As
//停止文件下载 Z"^@B2v
public void siteStop() enrmjA&3
{ E<4}mSn)
bStop = true; 68>zO%
for(int i=0;i<nStartPos.length;i++) ?d0Dfqh_
fileSplitterFetch.splitterStop(); :)yM9^<D
^KF'/9S
S\rfR N
} ;lEiOF+d
} +=8Po'E^!d
//负责部分文件的抓取 x}[` -
**FileSplitterFetch.java 6qDD_:F
*/ NNdS:(
package NetFox; #e=^[E-yE
!58JK f
~S6N'$^
import java.io.*; CYu8J@(\~g
import java.net.*; %G SSy_c
wz#n$W3mGf
e+WVN5"ID>
public class FileSplitterFetch extends Thread { )5v .9N6v
Qw-qcG
ZM.g+-9
String sURL; //File URL {XCrjO|
long nStartPos; //File Snippet Start Position ]]ZBG<#
long nEndPos; //File Snippet End Position 2fk
int nThreadID; //Thread's ID T{M:)}V
boolean bDownOver = false; //Downing is over c 1GP3
boolean bStop = false; //Stop identical Q!{Dw:7
FileAccessI fileAccessI = null; //File Access interface )1,&YJM*6l
cOgtBEhn
iy"Kg]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'W*F[U*&HP
{ rY= #^S
this.sURL = sURL; 463dLEd
this.nStartPos = nStart; }{y$$X<:
this.nEndPos = nEnd; BSf"'0I&
nThreadID = id; u\wd<<I']
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qh 3f
} xL"%2nf
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hH/O2
public void run() D=vq<X'
{ MO/N*4U2
while(nStartPos < nEndPos && !bStop) J|IDnCK
{ do,X{\
LfApVUm
DPx,qM#h5O
try{ K=)R!e8
URL url = new URL(sURL); DeSTo9A}!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4Ccb!?
httpConnection.setRequestProperty("User-Agent","NetFox"); A'8K^,<
String sProperty = "bytes="+nStartPos+"-"; mg(56)
httpConnection.setRequestProperty("RANGE",sProperty); k]iS3+nD
Utility.log(sProperty); ~=ktFuEa
bYc qscW
HWBom8u0
InputStream input = httpConnection.getInputStream(); 5aNDW'z`f
//logResponseHead(httpConnection); lg+g:o
Sq,ty{j2%
Qg!*=<b
byte[] b = new byte[1024]; zY+Et.lg]^
int nRead; 3(&F.&C$$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) EYG E#C; d
{ B_2>Yt"
nStartPos += fileAccessI.write(b,0,nRead); ZB&Uhi
//if(nThreadID == 1) Rp*t"HSaAW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^nF$<#a
} w#,v n8
R-fjxM*
f4_G[?9,
Utility.log("Thread " + nThreadID + " is over!"); QO/7p]$_
bDownOver = true; \[EWxu
//nPos = fileAccessI.write (b,0,nRead); auW]rwY
} O$/swwB!
catch(Exception e){e.printStackTrace ();} I+t38un%
} T}[vfIJD
} C>dJ:.K%H
iGk{8Da<
{B.]w9
//打印回应的头信息 y3]"H(
public void logResponseHead(HttpURLConnection con) %ko 8P
{ :<8V2
for(int i=1;;i++) ="R6YL
{ ie5ijkxZ(
String header=con.getHeaderFieldKey(i); EIQy?ig86
if(header!=null) nn:pf1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dRa<,@1"
Utility.log(header+" : "+con.getHeaderField(header)); :q<%wLs
else m4>oE|\
break; h_yR$H&tX
} S(h*\we
} %iC63)(M
y03a\K5[KQ
OZm[iH
public void splitterStop() D.R
{ s'Gy+h.
bStop = true; }{oBKm9_p
} #%"TU,[+
UO<claV
R7c)C8/~
} *AR<DXEL
-yGm^EwP
1>y=i+T/b
/* >%dAqYi $
**FileAccess.java ibs"Iv34
*//文件访问(定位，写) G%R`)Z]8&
package NetFox; G3^]Wwu
import java.io.*; rxp9B>~
6G$tYfX
RyWOiQk;
public class FileAccessI implements Serializable{ an[~%vxw}
d|+jCTKS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x>"JWD
RandomAccessFile oSavedFile; @~G`~8
long nPos; Atq2pL"
G0Tc}_o<Y
:vyf-K74M
public FileAccessI() throws IOException @b\_696.
{ To%*)a
this("",0); 'N ::MN
} S{7ik,Gdg
6x,=SW@4
>1pH 91c'
public FileAccessI(String sName,long nPos) throws IOException ={@ @`yP^$
{ 6Ok=q:;
oSavedFile = new RandomAccessFile(sName,"rw"); |P0L,R
this.nPos = nPos; i=H>D
oSavedFile.seek(nPos); H6S vU
} gs8@b5 RSb
9Sl|l.;!
XfK.Fj~-
public synchronized int write(byte[] b,int nStart,int nLen) gJ8 c]2c
{ D)7$M]d%
int n = -1; 0QH3,Ps1C
try{ MXJ9,U{<C'
oSavedFile.write(b,nStart,nLen); C{i;spc!bi
n = nLen; #]a51Vss
} vek:/'sj3p
catch(IOException e) JK]tcP
{ C*6)Ut '
e.printStackTrace (); y&=19A#
} "M0l;
k+r9h'd
cPaWJ+c
return n; lrX0c$)
} r5da/*G/O
z/&a\`DsU
Nz3%}6F:
} xXxh3 k\
N?{1'=Om
pW--^aHu
/* +y4AUU:Q
**SiteInfoBean.java ^pV>b(?qw
*/ bKMR7&e.Ep
package NetFox; \j})Kul
_u|FJTk
c^bk:=uj
public class SiteInfoBean { H?(SSL
KPd C9H
DcR}pQ(e
private String sSiteURL; //Site's URL 5h=TV
private String sFilePath; //Saved File's Path =<zSF\Zr_
private String sFileName; //Saved File's Name C"^hMsU8
private int nSplitter; //Count of Splited Downloading File X8SRQO^
\pD=Lv9
SP?U@w%}
public SiteInfoBean() chMc(.cN0
{//nSplitter的缺省值为5 fDEu%fUYZ
//default value of nSplitter is 5 }Wche/g`
this("","","",5); ]v\egfW,W
} ssyd8LC#
69j~?w)^
&<|-> *v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FJ(B]n[>
{ oYh<k
sSiteURL= sURL; i$^B-
sFilePath = sPath; Q$h:[_v
sFileName = sName; mV*/zWh_
this.nSplitter = nSpiltter; 8u'O`j
=6:L+V
T<e7(=
} *xo;pe)9
'tu@`7*
/sT ^lf=
public String getSSiteURL() cI%"Ynq"3
{ Q6!v3P/h
return sSiteURL; 9kX=99kf[
} =e!l=d|/
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g?[&0r1
public void setSSiteURL(String value) Ph+X{|
{ @6 ;oN
sSiteURL = value; r2GK_$vd
} r -q3+c^+
iA3>X-x
Ph#F<e(9
public String getSFilePath() p;u 1{
{ ./&zO{|0]
return sFilePath; ,s><kHJ
} E R]sDV
BF@5&>E
qQxA@kdd
public void setSFilePath(String value) V@_-H gg
{ (e8G (
sFilePath = value; ]Q4PbW
} WfDX"rA
M,t*nG
I!@s6tG
public String getSFileName() "\/^/vn?
{ _))I.c=v
return sFileName; QOV}5 0
} jkF+g$B
>^yc=mM(g3
/j' B\,
public void setSFileName(String value) F?8BS*r_
{ @ 2!C^}d3F
sFileName = value; .;HIEj zq
} J}(6>iuQY?
;;?vgrz
cZgMA8 F
public int getNSplitter() n|x$vgb
{ AUxM)H
return nSplitter; (/SGT$#8
} jWXR__>.
%0yS98']g
k6O.H
public void setNSplitter(int nCount) I%9bPQ
{ _^ q\XPS
nSplitter = nCount; j1puB
} Zn@W7c,_I
} 4O`6h)!NQ
l801`~*gO
cGE=.
/* Z6Nj<2u2
**Utility.java (A29ZH
*/ -!J2x8Ri
package NetFox; W}XYmF*_?
`l>93A
gwSN>oj &
public class Utility { /Fv/oY
0%s3Mp6H
L`UG=7r q
public Utility() Q PFeBl
{ P3iA(3I24<
X"[dQ_o
k7^R,.c@
} !TP6=ks
ohrw\<xsu
//线程睡眠 LY-lTr@A^
public static void sleep(int nSecond) }iilzE4oH#
{ "v(G7*2
try{ a`H\-G
Thread.sleep(nSecond); FUaI2
} FXx.$W
catch(Exception e) q*6q}s3n
{ JbE?a[Eg?
e.printStackTrace (); E-~mOYea
} iOT)0@f'
} [J0*+C9P*
OlMBMUR:
//日志 #B @X
public static void log(String sMsg) i`prv&
{ 2Co@+I[,4&
System.err.println(sMsg); j2|XDOf
} E: 9o;JU
% f2<U;ff
8>UKIdp
public static void log(int sMsg) Fr-[UZ~V
{ :GQUM6
System.err.println(sMsg); GR,J0LT
} Aoj6k\YX
} '_B_&is
]o-Fi$h!
7zD- ?%
/* * R%.a^R
**TestMethod.java /7bw: h;
*/ NQ?x8h3
package NetFox; n0_B(997*
: *ERRSL)
~&1KrUu&
public class TestMethod { *^'wFbaBO
ezp<@'0ZT
!#q{Z>H`
public TestMethod() <^xfcYx\
{ ///xx/weblogic60b2_win.exe L 5+J ^
try{ Aj,]n>{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #wr2imG6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,Ij=b
SiteFileFetch fileFetch = new SiteFileFetch(bean); QwBXlO?
fileFetch.start(); +p3 Z#KoC
} /Zc#j^_
catch(Exception e){e.printStackTrace ();} 2s 7mI'
sf`PV}a1
;4,'y
} tWm>j
J'W}7r
n!a<:]b<
public static void main(String[] args) kl" ]Nw'C
{ -Q#o)o
new TestMethod(); HOfF"QAR$
} qNpu}\L
} N[pZIH5ho=
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