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)); NvvD~Bb
} 4k!>JQor
for(int i=0;i<nEndPos.length-1;i++) G/ H>M%M
{ 40aD\S>
nEndPos = nStartPos[i+1]; lWDSF]ZYV
} *4/KK
nEndPos[nEndPos.length-1] = nFileLength; [9d\WPLC
} =)}Yw)
} P~84#5R1
!?" pnKb}
d ATAH}r&
//启动子线程 XVF!l>nE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p7W9?b9
for(int i=0;i<nStartPos.length;i++) 1,Jy+1G0w
{ jX.'G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1:RK~_E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GL _hRu
nStartPos,nEndPos,i); ^fV-m&F)K*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;{Yr|
fileSplitterFetch.start(); >`^;h]Q
} Gzp*Vr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XP[~ :+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); O;$}j:;KF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Fr-Vq=j&
nEndPos = " + nFileLength); 7[0<,O6Q
// fileSplitterFetch[nPos.length-1].start(); IH`7ou{
pd|l&xvka
J\FLIw4
//等待子线程结束 ]x66/O\0u
//int count = 0; MwX8FYF D
//是否结束while循环 C)~%(< D
boolean breakWhile = false; 3sgo5D-rMI
qC-4X"y+
l GJN;G7
while(!bStop) ~i.rk#{?D
{ 2V~uPZ
write_nPos(); E B! ,t
Utility.sleep(500); {b-SK5%]L
breakWhile = true; `<#O8,7`
W)^%/lAh
%q.5;L
for(int i=0;i<nStartPos.length;i++) I+`>e*:@W
{ &XW~l>!+
if(!fileSplitterFetch.bDownOver) )NTpb
{ BjHp3-A'
breakWhile = false; ti3S'K0t
break; qiq=v)
} a p(PI?]X
} "Xl"H/3r
if(breakWhile) UR(i_T&w
break; ItVVI"-
n'?]_z<
S_^;#=_c
//count++; O]?\<&y
//if(count>4) >jnx2$
// siteStop(); +:Nz_l
} I}|E_U1Qj
sLzZ}u?(
2IP<6l8N
System.err.println("文件下载结束！"); ?X\uzu
} /7ShE-.5#
catch(Exception e){e.printStackTrace ();} l\!`ZhM,
} \?|^w.
?T,a(m<i{
P)~olrf
//获得文件长度 9yu#G7
public long getFileSize() 1;!dTh
{ =L;g:hc<
int nFileLength = -1; NCYOY
try{ &x4*YMh
URL url = new URL(siteInfoBean.getSSiteURL()); 9j}Q~v\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9JeT1\VvHY
httpConnection.setRequestProperty("User-Agent","NetFox"); *g9VI;X
a/rQ@c>
xCyD0^KY
int responseCode=httpConnection.getResponseCode(); IR&b2FTcU
if(responseCode>=400) 1c*:" k
{ jF(R;?,
processErrorCode(responseCode); QtcYFf g
return -2; //-2 represent access is error sp_19u
} yNG|YB;
0LTsWCUQ6e
{cjp8W8hS
String sHeader; J<9}) m
K.}jyhKIKi
^rGuyW#
for(int i=1;;i++) e?\hz\^
{ .eCUvX`$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dIA1\;@
//Utility.log(in.readLine()); Wd7qpWItjQ
sHeader=httpConnection.getHeaderFieldKey(i); L"uidd0(g
if(sHeader!=null) H2+V1J=
{ DweF8c
if(sHeader.equals("Content-Length")) 76u\#{5
{ <W^>:!?w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cet|k!
break; 0}e&ONDQ
} yb\!4ml
} 7{VN27Fa_
else ']H*f2y
break; 6kONuG7Yv
} oJc7az
} &$h#9
catch(IOException e){e.printStackTrace ();} Bi0&F1ZC!
catch(Exception e){e.printStackTrace ();} LRdV_O1e6M
yATXN>]l
kZcGe*
Utility.log(nFileLength); @[5]?8\o
"msPH<D
}To-c'
return nFileLength; &}0#(Fa`
} J$(79gH{
2W/*1K}
o%h[o9i
//保存下载信息（文件指针位置） Zj)A%WTD,
private void write_nPos() 99[v/L>F
{ ZCDXy
try{ .]; `
output = new DataOutputStream(new FileOutputStream(tmpFile)); b\xse2#
output.writeInt(nStartPos.length); WmblY2
for(int i=0;i<nStartPos.length;i++) 1Nz#,IdQ
{ F[X;A\
// output.writeLong(nPos); yq` ,)
output.writeLong(fileSplitterFetch.nStartPos); u}jC$T>2%6
output.writeLong(fileSplitterFetch.nEndPos); |W SvAM3
} TezwcFqH
output.close(); %,udZyO3uR
} De49!{\a
catch(IOException e){e.printStackTrace ();} ?cD_\~
catch(Exception e){e.printStackTrace ();} ,(kaC.Em
} UFj/Y;
KwxJ{$|xH
ro^T L
//读取保存的下载信息（文件指针位置） *C(q{|f
private void read_nPos() #o(@S{(NZ
{ NOtwgZ-
try{ Bs<LJzS{V
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9}11>X
int nCount = input.readInt(); ^;cJjl'=
nStartPos = new long[nCount]; *35o$P46
nEndPos = new long[nCount]; !6*4^$i#o
for(int i=0;i<nStartPos.length;i++) '>% c@C[
{ }ct*<zj[~u
nStartPos = input.readLong(); 0Pg@%>yb~
nEndPos = input.readLong(); L$; gf_L
} o q cu<]
input.close(); K(}<L-cv
} %&4\'lE
catch(IOException e){e.printStackTrace ();} L$}'6y/@
catch(Exception e){e.printStackTrace ();} KI5099_/
} D o!]t7Y$
l4q7,%G
,jMV #H[
private void processErrorCode(int nErrorCode) 21\?FQrz
{ x_x|D|@wM
System.err.println("Error Code : " + nErrorCode); `wNJ*`
} Y\{lQMCy
"C9.pdP\8
|r53>,oR<:
//停止文件下载 A|P `\_
public void siteStop() "QV1G'
{ t($z+C<
bStop = true; $dHD
for(int i=0;i<nStartPos.length;i++) '8fh(`
fileSplitterFetch.splitterStop(); B4;P)\2
IV$2`)[A&X
r7N%onx
} yykyvy
} 8R.`*
//负责部分文件的抓取 3S1`av(tD
**FileSplitterFetch.java Uc|MfxsL
*/ 2N_9S?a3sK
package NetFox; Px"K5c*
x8*@<]!
y1hJVYE2
import java.io.*; 2v\-xg%1
import java.net.*; Jl,\^)DSw
&8 4Izs/[
6c&OR2HGqO
public class FileSplitterFetch extends Thread { cOEzS
Q*AgFF%wn
JZrUl^8E
String sURL; //File URL U*em)/9
long nStartPos; //File Snippet Start Position &0S/]E`_M
long nEndPos; //File Snippet End Position J*O$)K%Hx
int nThreadID; //Thread's ID 8rsv8OO
boolean bDownOver = false; //Downing is over &b&o];a
boolean bStop = false; //Stop identical 98eS f
FileAccessI fileAccessI = null; //File Access interface VR0#"
esQRg~aCGy
uDi#a~m@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wH[}@w
{ pvJPMx
this.sURL = sURL; W'9=st'
this.nStartPos = nStart; k|T0Bly3P
this.nEndPos = nEnd; j>OB<4?.+
nThreadID = id; bwAL:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4\yKd8I
} I3V>VLv
>#\&%0OZw
mDp|EXN
public void run() .U !;fJ9
{ D`^9 u K
while(nStartPos < nEndPos && !bStop) lCyp&b#(L
{ n`hes_{,g
5K*-)F ]
QP e}rQnm
try{ %lU$;cY
URL url = new URL(sURL); ai,Mez
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jP";ll|c
httpConnection.setRequestProperty("User-Agent","NetFox"); qlg~W/
String sProperty = "bytes="+nStartPos+"-"; G{ $Zg
httpConnection.setRequestProperty("RANGE",sProperty); O({-lI
Utility.log(sProperty); /vB%gqJvX
9bT,=b;
VRoeq {
InputStream input = httpConnection.getInputStream(); $*H>n!&
//logResponseHead(httpConnection); u[oYVpe)IG
wWflZ"%
Sk$XC
byte[] b = new byte[1024]; 2g^Kf,m
int nRead; k>Qr14F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7j&l2Z
{ qD4e] 5
nStartPos += fileAccessI.write(b,0,nRead); [M2,bc8SJV
//if(nThreadID == 1) ]IJ.}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @11voD
} MnsnW{VGX
>|7&hj$
6SsZK)X
Utility.log("Thread " + nThreadID + " is over!"); %2oLND}?z
bDownOver = true; tO?*x/XC{
//nPos = fileAccessI.write (b,0,nRead); Q;5'I3w
} Li=l/
catch(Exception e){e.printStackTrace ();} Dl/UZ@8pl
} ,lA J{5\#
} OG 5n9sx
>e-XZ2>Sj
+U%lWE%
//打印回应的头信息 /IV:JVT
public void logResponseHead(HttpURLConnection con) [dU/;Sk5
{ K{>O.5
for(int i=1;;i++) p|Rxy"}
{ &[\rnJ?D
String header=con.getHeaderFieldKey(i); Punbw\9!d,
if(header!=null) 2 >xV&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )vGRfFjw_
Utility.log(header+" : "+con.getHeaderField(header)); ^#^u90I
else Z*]n]eS
break; R?|_`@@A
} a/)TJv
} (%+DE4?
<JH0 &
nI_Zk.R
public void splitterStop() *%)L?*
{ l]v *h0!
bStop = true; ^<|If:|
} Y@.JW
& bw1
l1W5pmhK]'
} 6gR=e+
=h_4TpDQ
{8B\-LUR
/* ":-)mfgGU
**FileAccess.java p-(Z[G*
*//文件访问(定位，写) Fsq S)
package NetFox; Bxa],inuZ
import java.io.*; .PAkW2\#
2Vu|uZd
fnmZJJ,Q
public class FileAccessI implements Serializable{ )Y *?VqZn
ZXUe4@qfl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -I_lCZ{Nbi
RandomAccessFile oSavedFile; 5W{>5.Arx)
long nPos; 9lD,aOb
I8Zp#'|U
!<YRocQY
public FileAccessI() throws IOException BO9Z"|"
{ %cm5Z^B1"
this("",0); .y\HQ^j
} 3tm z2JIb
.e"jnP~
q?^0 o\
public FileAccessI(String sName,long nPos) throws IOException :,ym)|YV
{ ?\O+#U%W
oSavedFile = new RandomAccessFile(sName,"rw"); ]Z84w!z
this.nPos = nPos; H]!y |p
oSavedFile.seek(nPos); 7GIv3Dc
} 4KM$QHS5{
4vX]c
8uGPyH
public synchronized int write(byte[] b,int nStart,int nLen) LNN:GD)>
{ @LE?XlhD
int n = -1; n47=eKd70
try{ !:n),sFv45
oSavedFile.write(b,nStart,nLen); aEk*-v#{
n = nLen; 6>L.)V
} ^2AF:(E
catch(IOException e) >=`c [=:Z_
{ rgYuF,BT.
e.printStackTrace (); x ?V/3zW
} 3'"M31iA
j^ _I{
!Q(xOc9>Ug
return n; ^i8I 1@ =
} `HM3YC
5j{@2]i
Me}TW!GC
} B@;)$1-UT
NI1HUUZz
*3/7wSV:
/* gZjOlp
**SiteInfoBean.java S[a5k;8GL
*/ 3opLLf_g
package NetFox; Z8&C-yCC
E~>6*_?
^c\IZ5
public class SiteInfoBean { K7hf m%`N
L, {rMLM%
bJ|?5
private String sSiteURL; //Site's URL p0rwiBC=q
private String sFilePath; //Saved File's Path O8r"M8
private String sFileName; //Saved File's Name 2\w=U,;(
private int nSplitter; //Count of Splited Downloading File h6h1.lZ
|nEVOy>'
PEBFN
public SiteInfoBean() >fye^Tx
{//nSplitter的缺省值为5 &#@>(u:.
//default value of nSplitter is 5 qP"JNswI_
this("","","",5); f%{Tu`
} 'Y[A'.*}4
4VNb`!e
T'M66kg
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Fd[h9 G
{ rh`.$/^
sSiteURL= sURL; + |qfgi
sFilePath = sPath; (b%y$D
sFileName = sName; d_C4B
this.nSplitter = nSpiltter; sdf%
b;L>%;
F:J7|<J^F
} <s8? Z1
g?~Tguv
m`$>:B
public String getSSiteURL() tQ~<i %;
{ nnE_OK!}T
return sSiteURL; |:9Ir^
} _E6}XNS
_IL2-c8
7"q+"0G
public void setSSiteURL(String value) ck+b/.gw`
{ iS"8X#[]N
sSiteURL = value; D;zWksq
} HmExfW
fYhR#FVI
G*\abL
public String getSFilePath() xHB/]Vd-
{ h}|6VJ@.
return sFilePath; xP/OsaxN
} 0)AM-/"
YZGS-+
mF'-Is
public void setSFilePath(String value) uuSR%KK]|
{ !7*(!as
sFilePath = value; $J"%I$%X=
} yW\XNX
pp~3@_)b
yGvDn' m
public String getSFileName() fw' r.
{ mz\NFC<
return sFileName; _BV`,`8}
} ,?g=U8y|
r<*O
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public void setSFileName(String value) 3ai (x1%
{ \=!H2M
sFileName = value; yo'9x s
} lC#RNjDp/~
3J%V%}mD
ImIqD&a-h
public int getNSplitter() HG2GZ}~^1
{ upypxC
return nSplitter; k-"<{V
} pW\z\o/2
QDS0ejhp
vwKw?Z0%J
public void setNSplitter(int nCount) 3AURzU
{ rA,CQypo
nSplitter = nCount; G0}Dq MTi
} (ZV;$N-t
} 3bH~';<
{Eu'v$c!
9x=3W?K:,
/* @\)fzubu
**Utility.java p*|ah%F6N
*/ td >,TW=A*
package NetFox; OX+hZ<y
Gn59yG!4
ic-IN~J-
public class Utility { {I{3(M#"
nq'M?c#E
-Q$b7*"z(
public Utility() &]< 3~6n
{ 1Bg_FPu
lkA^\+Ct
3_W{T@T
} ?E<c[*F05
.+yW%~0
//线程睡眠 3B{[%#vO
public static void sleep(int nSecond) HzvlF0f
{ R\5Vq$Q
try{ 3OP.12^
Thread.sleep(nSecond); B'}"AC"
} _ h9o@
catch(Exception e) +TN^NE
{ =&7@<vBpy
e.printStackTrace (); Ox qguT,
} (a.1M8v+Sg
} 9tK>gwb
/p)F>WR
//日志 ?x3Jv<G0*
public static void log(String sMsg) m'x;,xfY&F
{ Es.nHN^]%K
System.err.println(sMsg); c@R; /m:R
} *Qkc[XHqy
{)@D`{$
y-B=W]E
public static void log(int sMsg) |~K(F<;j
{ MBw-*K'?zB
System.err.println(sMsg); %NajFjBI
} K2rzhHfb
} &yIGr`;
?6P.b6m}0
S1bAu <
/* ZFvyL8o
**TestMethod.java E0l_--
*/ -5bA $
package NetFox; gfy19c 9
8=;k"
\9:wfLF8!
public class TestMethod { 5`-UMz<]
{fDTSr?/
UBZ9A
public TestMethod() qpp/8M
{ ///xx/weblogic60b2_win.exe edvFQ#,d
try{ jz'<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5[gh|I;D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2/7_;_#vJ%
SiteFileFetch fileFetch = new SiteFileFetch(bean); _yH`t[
fileFetch.start(); :c.JhE3D
} /)>S<X
catch(Exception e){e.printStackTrace ();} K#mOSY;}
-YGbfd<wq
},@^0UH4c
} oPQtGl p
BR5BJX
X~9j$3lUBR
public static void main(String[] args) !mJo'K
{ Vb|#MNf)
new TestMethod(); /JJw 6[N
} h9s >LY
} '0RwO[A#1
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