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)); upefjwm
} Bf+7;4-
for(int i=0;i<nEndPos.length-1;i++) svj0;x5
{ u~7 ,v
nEndPos = nStartPos[i+1]; ~Kll.
} )|Md"r_B
nEndPos[nEndPos.length-1] = nFileLength; =H)"t:xE
} X0&[cyP!
} D%,AdR"m
fKQq]&~ H
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//启动子线程 >u/ T`$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <xO" E%t
for(int i=0;i<nStartPos.length;i++) wu`P=-
{ D\9-MXc1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E5`KUMZkq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $9PscubM4
nStartPos,nEndPos,i); gzd)7np B2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W"&Y7("y
fileSplitterFetch.start(); ITr@;@}c]
} vq;_x
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^wTod\y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); xu(N'l.7&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M9dOLM.
nEndPos = " + nFileLength); U_l#lGA(H
// fileSplitterFetch[nPos.length-1].start(); }MCJ$=5
Lju)q6
x17K8De
//等待子线程结束 Kq4b`cn{_
//int count = 0; K'u66%wAL
//是否结束while循环 }35HKgqX
boolean breakWhile = false; s:f%=4-7
)a0%62
;($"_h
while(!bStop) m{{8#@g
{ F?*ko,
write_nPos(); JR^#NefJ
Utility.sleep(500); N2/t
breakWhile = true; `zjbyY
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for(int i=0;i<nStartPos.length;i++) riz[AAB
{ d%w#a3(
if(!fileSplitterFetch.bDownOver) aA3KJa
{ C'oNGOEd
breakWhile = false; ~3r}6,%
break; Hy| X>Z
} $#LR4 [Fq
} }n[<$*W^
if(breakWhile) k%2Rv4)hU
break; 2GW.'\D
OHyBNJ
^!yJ;'H\
//count++; ai@hQJ*
//if(count>4) l?J|Ip2W
// siteStop(); WIkr0k
} D N#OLk
ZGZ+BOFL
#!RO,{FT
System.err.println("文件下载结束！"); *Iir/6myM
} ._A@,]LS}
catch(Exception e){e.printStackTrace ();} ^Z`?mNq9
} lVR a{._m
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1?hx/02
//获得文件长度 %9Y3jB",2
public long getFileSize() dRu|*s
{ G ;fc8a[X
int nFileLength = -1; {-Q=YDR
try{ Trz41g
URL url = new URL(siteInfoBean.getSSiteURL()); "o6a{KY(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ux=0N]lc
httpConnection.setRequestProperty("User-Agent","NetFox"); A$;"9F@
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*!-J"h
int responseCode=httpConnection.getResponseCode(); 9W+RUh^W
if(responseCode>=400) KE*8Y4#9
{ 7,:$, bL
processErrorCode(responseCode); pxgVYr.
return -2; //-2 represent access is error j$mCU?
} lOJ3_8
f'28s*n
QxS=W2iN
String sHeader; Qqn9nO9
C<u<:4^H
ObIL w
for(int i=1;;i++) w/UZ6fu
{ J_ y+.p- 5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); nBo?r}t4
//Utility.log(in.readLine()); # @~HpqqR
sHeader=httpConnection.getHeaderFieldKey(i); qr|v|Ejd~
if(sHeader!=null) @kmOz(
{ KCc7u8
if(sHeader.equals("Content-Length")) @M_p3[c\
{ "CcdwWM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >Ndck2@
break; #cdrobJ
} ~;uc@GGo
} ^oYudb^%
else unZYFA}(
break; A1uo@W
} `Eq~W@';Q0
} MeMSF8zSQ
catch(IOException e){e.printStackTrace ();} NPY\ >pf
catch(Exception e){e.printStackTrace ();} f&ri=VJY\T
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VsR8|Hn$
Utility.log(nFileLength); L^><APlX
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4te QG
return nFileLength; bWEti}kW
} ;I@@PUnR
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\[yg f6#[
//保存下载信息（文件指针位置） guc[du
private void write_nPos() \Jy/ a-
{ }?KfL$@$
try{ ]sL)[o
output = new DataOutputStream(new FileOutputStream(tmpFile)); K#_x.:<J
output.writeInt(nStartPos.length); ecIZ+G)k
for(int i=0;i<nStartPos.length;i++) & Y Y^Bd#
{ !wNj;ST*
// output.writeLong(nPos); 'wm :Xa
output.writeLong(fileSplitterFetch.nStartPos); M`u&-6
output.writeLong(fileSplitterFetch.nEndPos); op5G}QZ
} Tc.k0n%W:b
output.close(); BK;Gh0mp
} U?.cbB,
catch(IOException e){e.printStackTrace ();} Oll,;{<O
catch(Exception e){e.printStackTrace ();} TP R$oO2
} f:hsE
wR]jJbF
?CU6RC n
//读取保存的下载信息（文件指针位置） Ww)p&don
private void read_nPos() yDe6f(D
{ pB0p?D)n
try{ O~~WP*N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); BWG*UjP M
int nCount = input.readInt(); ~>-MVp
nStartPos = new long[nCount]; .0]\a~x
nEndPos = new long[nCount]; 6zR9(c:a~
for(int i=0;i<nStartPos.length;i++) *}<Uh'?
{ 7uq/C#N
nStartPos = input.readLong(); 8urX]#
nEndPos = input.readLong(); QMAineO
} 2/F";tc\'
input.close(); i&_&4
} lNRGlTD%
catch(IOException e){e.printStackTrace ();} SR8)4:aKW
catch(Exception e){e.printStackTrace ();} l\t\DX"s_
} -'%>Fon
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1r?hRJ:'
private void processErrorCode(int nErrorCode) 0+dc
{ u(W+hdTap=
System.err.println("Error Code : " + nErrorCode); wY'w'%A?
} ?_V&~?r
`G0GWh)`x
egXbe)ld
//停止文件下载 :/<SJ({q
public void siteStop() Q}6!t$Vk
{ [@;q#.}Z
bStop = true; ,*MAteD
for(int i=0;i<nStartPos.length;i++) (<KFA,
fileSplitterFetch.splitterStop(); xP+`scv*m#
*l{GD1ZDk
}p|S3/G?$!
} 2&o jQhe
} I6-.;)McO
//负责部分文件的抓取 0ub0[A
**FileSplitterFetch.java >K;DBy*
*/ =IH~:D\&
package NetFox; 6 @A'N(I=O
Mv?$zV"`#
wSd|-e
import java.io.*; ;Y9-0W
import java.net.*; ?[VL 2dP0
MP_LdJM1E
[L ?^+p>
public class FileSplitterFetch extends Thread { {16]8-pe
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&,8F!)[9
String sURL; //File URL J5Ovj,[EZ
long nStartPos; //File Snippet Start Position ;1AXu/
long nEndPos; //File Snippet End Position m-u0U
int nThreadID; //Thread's ID slTE.
boolean bDownOver = false; //Downing is over q/#pol
boolean bStop = false; //Stop identical J:Idt}@z
FileAccessI fileAccessI = null; //File Access interface /nWBol,
SUC'o"
E*AI}:or;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @s.civ!Yk
{ sXaudT
this.sURL = sURL; 'zhv#&O
this.nStartPos = nStart; l9t|@9
this.nEndPos = nEnd; v|Y ut~
nThreadID = id; B&L-Lc2
fileAccessI = new FileAccessI(sName,nStartPos);//定位 xQ,My
} 5RsO^2V:
/ DG t
ItD&L ))
public void run() ~YRG9TK
{ oH='\M%+
while(nStartPos < nEndPos && !bStop) zQ~ax!}R
{ kt2W7.A5
zI,z<-
<BiSx
try{ /Os6i&;
URL url = new URL(sURL); A9_}RJ9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !9t,#?!
httpConnection.setRequestProperty("User-Agent","NetFox"); `n?Rxhkwp
String sProperty = "bytes="+nStartPos+"-"; dt||nF
httpConnection.setRequestProperty("RANGE",sProperty); ZA+w7S3
Utility.log(sProperty); ^).
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F}~qTF;H
InputStream input = httpConnection.getInputStream(); Bwl@Muw
//logResponseHead(httpConnection); 6UKZ0~R
5=_bK^Am
Tx>V$+al
byte[] b = new byte[1024]; {n\Ai3F-
int nRead; gY&WH9sp?9
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s[bQO1g;*
{ \IaUsx"#o{
nStartPos += fileAccessI.write(b,0,nRead); I%:\"g"c
//if(nThreadID == 1) U#Wg"W{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WZM
} UR~s\m
$f?GD<}?7r
v>0I=ut
Utility.log("Thread " + nThreadID + " is over!"); Z`<5SHQd
bDownOver = true; bH.SUd)
//nPos = fileAccessI.write (b,0,nRead); H/U.Bg 4
} v\o m
catch(Exception e){e.printStackTrace ();} ezb*tN!
} C#LTF-$])
} />n!2'!
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\`;1[m
//打印回应的头信息 ;,/4Ry22j-
public void logResponseHead(HttpURLConnection con) "H#pN;)+
{ 5.$/]2VK
for(int i=1;;i++) @jCMQYR
{ %xrldn%
String header=con.getHeaderFieldKey(i); 3i1TBhs6
if(header!=null) Ae\:{[c_D
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6WX?Xc]$3
Utility.log(header+" : "+con.getHeaderField(header)); &=]!8z=
else 3Cgv($xl&
break; "5204I
} -tIye{
} iPdS>ee
21O@yNpS$
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public void splitterStop() I?RUVs
{ I? ="Er[g}
bStop = true; >n3ig~0d
} p:V1VHT,
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}kG>6_p?
} Rl&nR$#
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,xg-H6Xfa{
/* T|,/C|L
**FileAccess.java .W\JvPTC
*//文件访问(定位，写) +%H=+fJ2}
package NetFox; x_t$*
import java.io.*; ^WF_IH&
W_6gV
=ld!=II
public class FileAccessI implements Serializable{ $_3)m
6"?#E[ #[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !jf!\Uu[U
RandomAccessFile oSavedFile; ep4?;Qmho
long nPos; W[R`],x`
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Po&'#TC1
public FileAccessI() throws IOException # [ +n(
{ pedyWA>
this("",0); T"t.t%(8
} +:W/=C d(h
ht#,v5oG>f
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public FileAccessI(String sName,long nPos) throws IOException @Ko#nDEq
{ -/ G#ls|?
oSavedFile = new RandomAccessFile(sName,"rw"); `n@;%*6/
this.nPos = nPos; hXvC>ie(i
oSavedFile.seek(nPos); ;66{S'*[
} 3-oKY*jO
Vju/+
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public synchronized int write(byte[] b,int nStart,int nLen) zJ$U5r/u
{ <,Pl31g^
int n = -1; l[i1,4
try{ [+8*}03
oSavedFile.write(b,nStart,nLen); }t:*w
n = nLen; ]TJ258P}
} /E3~z0
catch(IOException e) 'y5H%I!
{ -?l`LbD
e.printStackTrace (); @-Y,9mM
} M2;6Cz>,P
@REMl~"D5
xs )jO+.
return n; R#i`H(N
} 2a;[2':
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Al]*iw{
} O\gVB!x
&-w.rF@
]q"y P0
/* 7{l~\]6d
**SiteInfoBean.java C4GkFD
*/ r i)`e
package NetFox; Ms5R7<O.7
_2)QL
0fLd7*1>
public class SiteInfoBean { -knP5"TB
=Ot_P7'5gv
Gx4{ 9
private String sSiteURL; //Site's URL )TyP{X>
private String sFilePath; //Saved File's Path ]826kpq_
private String sFileName; //Saved File's Name j<6+p r
private int nSplitter; //Count of Splited Downloading File |j{]6Nu
sCmN|Q
aK]AhOG
public SiteInfoBean() sl"H!cwF
{//nSplitter的缺省值为5 tK?XU9o
//default value of nSplitter is 5 7G7"Zule*j
this("","","",5); pe>?m^gz[
} Jw>na _FJ
2kk; z0f
A`Rs n\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -%Ce
{ =diGuIB
sSiteURL= sURL; rg=Ym.
sFilePath = sPath; K`j:F>b
sFileName = sName; $~j9{*]5
this.nSplitter = nSpiltter; IxG7eX!
]>ndFE6kl
dc_2nF
} PRNq8nmxC
; xQhq*
nywC]T
public String getSSiteURL() keG\-f
{ Dd,i^,4Gj
return sSiteURL; -1~o~yGE
} AX'-}5T=
Ino]::ZJ/
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public void setSSiteURL(String value) @,}tY ?>a
{ M ac?HI
sSiteURL = value; \zwm:@lG
} s,pg4nst56
NxDVU?@p*
m8G/;V[x
public String getSFilePath() fU\;\
{ a,)/D_{1
return sFilePath; ksJ 1:_
} ImD&~^-_<
'NCx<0*
$ER9u2
public void setSFilePath(String value) F-M)6&T
{ 'H4?V
sFilePath = value; B2KBJ4rI[1
} FFe{=H,=
p:eaZ
"q!*RO'a
public String getSFileName() l8 $.k5X
{ \qlz<
return sFileName; vlipB}
} c/:k|x
\m1^sFMZ
d2)]6)z6
public void setSFileName(String value) U[OUIXUi
{ q}0I`$MU
sFileName = value; 4Ssy (gt
} Fey^hx w =
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public int getNSplitter() t<$J 3h/"
{ ;O5Iu
return nSplitter; ep Dp*
} J83C]2~7
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VVpJ +
public void setNSplitter(int nCount) M'oZK
{ \3%3=:
nSplitter = nCount; S v#,L8f
} MZh?MaBz06
} \:'6_K
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L/%{,7l<^?
/* kA)`i`gt
**Utility.java #XqiXM~^R
*/ y@7CY-1
package NetFox; OsVz[wN
9C7HL;MF
Fg'{K%t4
public class Utility { g[~J107%A
h0$ \JXk
Nez '1
public Utility() x{GFCy7
{ so| U&`G
<X5ge>.
$fT#Wva-\d
} 0>e]i[P.
%nE%^Enw
//线程睡眠 l8_RA
public static void sleep(int nSecond) vq-;wdq?2
{ _J#oAE5]!
try{ /F''4%S?E
Thread.sleep(nSecond); hx/A215L
} b^()[4M;
catch(Exception e) Goy[P2m
{ z(2G"}
e.printStackTrace (); ~Ga{=OM??
} A`>^A]%
} 5~(nHCf>
w\V<6_[vv.
//日志 ]"YXa~b
public static void log(String sMsg) "gDk?w
{ JE*?O*&|Q
System.err.println(sMsg); F[F NtZ
} olXfR-2>1
/q7$"wP
>?G!>kw
public static void log(int sMsg) ljz=u;O)
{ EU'rdG*t/R
System.err.println(sMsg); k)y<iHR_o
} A1z<2.R
} Y$j!-l5z
[ :Sl~
[D<(xr&N%
/* r?^L/HGc
**TestMethod.java }jFRuT;35
*/ PpNG`_O
package NetFox; ^EW6}oj[
/'_Yct=
hw)z]
public class TestMethod { J9y}rGO
g0s4ZI+T
CDr0QM4k:.
public TestMethod() LcNI$g;}Yf
{ ///xx/weblogic60b2_win.exe R?N+./{
try{ Nd@/U c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 02(Ob
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c|(Q[=
SiteFileFetch fileFetch = new SiteFileFetch(bean); $YJi]:3&
fileFetch.start(); wsc=6/#u
} 3vQVk
catch(Exception e){e.printStackTrace ();} m")p]B&i=
0Jd>V
AI,E9
} 300[2}Y]
9+.3GRt7
/c4$m3?]
public static void main(String[] args) L}_VT J
{ (l(d0g&p>
new TestMethod(); |Vu`-L'Jz
} ORXH<;^0y
} &XXr5ne~C
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