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)); `B^?Za,xN
} 8(ZQD+U(9F
for(int i=0;i<nEndPos.length-1;i++) tv?~LJYN
{ z/;NoQ-
nEndPos = nStartPos[i+1]; M T{^=F ]
} ptUnV3h
nEndPos[nEndPos.length-1] = nFileLength; W/+|dN{O+g
} NjMo"1d
} 7^:s/xHO*
9g>ay-W[(
0C0iAp
//启动子线程 BB~Qs
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $o-s?";
for(int i=0;i<nStartPos.length;i++) 73P(oVj<
{ ]0\8g=KK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SA}]ZK P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]2v31'
nStartPos,nEndPos,i); W~gFY#w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); sYeZ.MacU
fileSplitterFetch.start(); vZ|m3;X
} `m3C\\9;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '?q|7[SU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Yj;$hV8j(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cz.-cuD[iD
nEndPos = " + nFileLength); Tl9_Wi
// fileSplitterFetch[nPos.length-1].start(); {Rbc
g{dyDN$5|w
<~f/T]E,
//等待子线程结束 2<<,aL*
//int count = 0; GT*\gZ
//是否结束while循环 .\i9}ye
boolean breakWhile = false; y|c]r!A
=:5yRP
U+nwLxe'
while(!bStop) .(3B}}gB>
{ YMJ?t"
write_nPos(); I2D<~xP~2+
Utility.sleep(500); xUj[d(q
breakWhile = true; Rh~<#"G]
z%]~^k8
5q" ;R$+j
for(int i=0;i<nStartPos.length;i++) :0V<
{ o^gqpQv
if(!fileSplitterFetch.bDownOver) aQkgkV;~
{ CkIICx
breakWhile = false; HZ]'?&0
break; LkNC8V
} /G\-v2iD
} % &{>oEQ
if(breakWhile) :Iw)xd1d}\
break; YQ2ie>C8
m &s0Ub
=XyK/$
//count++; [O9(sWL'
//if(count>4) )7:2v1Xr]
// siteStop(); nB"q
} "o%N`Xlx
7@MVInV9
oO!@s`
System.err.println("文件下载结束！"); S+_}=25
} tOS%.0W5J
catch(Exception e){e.printStackTrace ();} X,^J3Ek>O
} i3N _wv{
qH$G_R#)8B
fq_6xs
//获得文件长度 q4Qm:|-
public long getFileSize() )k=8.j4
{ [\eUCt F
int nFileLength = -1; "wA3l%d[Y
try{ ,Rz,[KI|
URL url = new URL(siteInfoBean.getSSiteURL()); iiKFV>;t/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (lT H EiX
httpConnection.setRequestProperty("User-Agent","NetFox"); ME{i-E4
bvs0y7M='
cKdy)T%;
int responseCode=httpConnection.getResponseCode(); ~cQP4 kBD]
if(responseCode>=400) i$$\}2m{L
{ 7[^:[OEE
processErrorCode(responseCode); qFt%{~a S
return -2; //-2 represent access is error }yC ve
} nSmYa7
tk2B\}6
=^O84Cp 6
String sHeader; `)!)}PXl
Hk(w\
&EV|knW
for(int i=1;;i++) ngn%"xYX
{ qqLmjDv
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3Ud&B
//Utility.log(in.readLine()); 'R99kL/.N
sHeader=httpConnection.getHeaderFieldKey(i); uXyNj2(d.
if(sHeader!=null) G{$9e}#
{ wlmi&kq
if(sHeader.equals("Content-Length")) 4f'WF5S/}8
{ :/K 'P`JaL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ds$FO}KD{
break; ,H[-.}OO
} 78Nli/U
} VNx}ADXu]
else e*:[#LJ]C
break; E&jngxlN
} mRxL%!
} w[UPoG #Uh
catch(IOException e){e.printStackTrace ();} ;9/6X#;$
catch(Exception e){e.printStackTrace ();} .9S
s=u0M;A0Q
YLJH?=2@
Utility.log(nFileLength); O"nY4
(/Hq8o-Fw
\bZbz/+D
return nFileLength; (+q?xwl!N
} o#4Wn'E
wwmMpK}f
LPvyfD;Zy
//保存下载信息（文件指针位置） Gq$9he<
private void write_nPos() 2P"@=bYT"
{ x.<^L] "
try{ (S=::ODU
output = new DataOutputStream(new FileOutputStream(tmpFile)); #sq-V,8
output.writeInt(nStartPos.length); w[n|Sauy,
for(int i=0;i<nStartPos.length;i++) 3T|:1Nw
{ gjk=`lU
// output.writeLong(nPos); VgN`' iC`I
output.writeLong(fileSplitterFetch.nStartPos); VABrw t
output.writeLong(fileSplitterFetch.nEndPos); gh['T,
} QSmE:Y
output.close(); 9L*gxI>
} ,iB)8Km@U
catch(IOException e){e.printStackTrace ();} mAX]m1s
catch(Exception e){e.printStackTrace ();} )U`H7\*)
} j}X4#{jgC
^-f5;B`\i
JU1U=Lu."
//读取保存的下载信息（文件指针位置） _Oh;._PS
private void read_nPos() WIQt5=-
{ 69`9!heu
try{ l)Q,*i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bv)E>%Yy
int nCount = input.readInt(); Z:&"Ax
nStartPos = new long[nCount]; b^;19]/RW
nEndPos = new long[nCount]; t9zPJQlT}
for(int i=0;i<nStartPos.length;i++) GKZn|<Y|{c
{ axxdW)+K
nStartPos = input.readLong(); "/O0j/lm
nEndPos = input.readLong(); <u&uwD~A
} =5+M]y E<
input.close(); >Czcs=(L.k
} = K"F!}
catch(IOException e){e.printStackTrace ();} psta&u\ q
catch(Exception e){e.printStackTrace ();} \@:pWe
} @|j`I1r.A
:nd }e
tI{pu}/"#
private void processErrorCode(int nErrorCode) #z6RzZu
{ )><cL:IJ}S
System.err.println("Error Code : " + nErrorCode); R5H UgI
} wGBQ.Ve[
'.#KkvE##
aGr(djD
//停止文件下载 (t&P.N/
public void siteStop() T=ox;r
{ +7|Oy3s
bStop = true; qWy{{A+
for(int i=0;i<nStartPos.length;i++) CDO_A\
fileSplitterFetch.splitterStop(); MVe5j+8
q}M^i7IE
C' o4Su#
} 3Nsb@0
} @433?g`2b
//负责部分文件的抓取 @j9yc
**FileSplitterFetch.java Z@RAdwjR`p
*/ 'lHtz~[
package NetFox; :{E3H3
Fu^^Jex
7Aq4YjbX
import java.io.*; ]zhFFq`
import java.net.*; <T+Pw7X
$lU~3I)
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public class FileSplitterFetch extends Thread { R0gjx"U
F'C]OMBE
+G7A.d`V}
String sURL; //File URL g5M-Vu
long nStartPos; //File Snippet Start Position |2 g }i\
long nEndPos; //File Snippet End Position Z@t).$
int nThreadID; //Thread's ID U:J~Oy_Z
boolean bDownOver = false; //Downing is over hh|'Uq3
boolean bStop = false; //Stop identical !:c7I@
FileAccessI fileAccessI = null; //File Access interface "sUe:F;
VS%8f.7ep
qusgX;)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BaR9X ?~O$
{ ]Q6,,/nn
this.sURL = sURL; Q5Y4@
this.nStartPos = nStart; JLT':e~PX
this.nEndPos = nEnd; "3Ag+>tuRW
nThreadID = id; bO9F rEz5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R 7xV{o
} f]J?-ks
5u~Ik c~
kFw3'OZ,
public void run() P+%O]v1 Ob
{ 9cQKXh:R.
while(nStartPos < nEndPos && !bStop) x1|5q/I
{ oQjh?vm
pn{.oXomf
jO3Q@N0_
try{ E-E+/.A
URL url = new URL(sURL); dU:s^^f&R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TJ?}5h5
httpConnection.setRequestProperty("User-Agent","NetFox"); p!hewtb5
String sProperty = "bytes="+nStartPos+"-"; 1[} =,uaM
httpConnection.setRequestProperty("RANGE",sProperty); |uj1T=ZY
Utility.log(sProperty); DS=kSkW^&5
~ Y4H)r
Mff_j0D
InputStream input = httpConnection.getInputStream(); E@0wt^
//logResponseHead(httpConnection); A}t.`FLP,j
FK }x*d
wZE[we^Q"
byte[] b = new byte[1024]; RLw=y{%p
int nRead; !D7\$ g6g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \X Nb9-
{ qVZ=:D{
nStartPos += fileAccessI.write(b,0,nRead); wrK$ZO]
//if(nThreadID == 1) O<L/m[]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SKD!V6S
} o7DDL{iR/
'gI58#v
j;VYF
Utility.log("Thread " + nThreadID + " is over!"); !`=r('l
bDownOver = true; G?<L{J2"Q
//nPos = fileAccessI.write (b,0,nRead); 3|/ ;`KfQ
} v srce
catch(Exception e){e.printStackTrace ();} ;s9!ra:3
} X'7 T"5!
} #y-OkGS ^
bsP:tFw>
0=t_a]+
//打印回应的头信息 AH`tkPd
public void logResponseHead(HttpURLConnection con) O JvEq@
{ uLe+1`Y5Ux
for(int i=1;;i++) dbB2/RI
{ *>$'aQ
String header=con.getHeaderFieldKey(i); sFC1PdSk4T
if(header!=null) A>R ^iu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }\JoE4
Utility.log(header+" : "+con.getHeaderField(header)); nITr5$f
else riFE.;
break; _~HGMC)
} `zZ=#p/
} e%wbUr]c2
h*_r=' E
o'>jO.|
public void splitterStop() <2}"Y(zwKl
{ x03GJy5
bStop = true; ]A<\d
} 14s+&
0EPF; Xx
\n`UkxZn+
} z<: 9,wtbP
7:jSP$
%do|>7MO@
/* YjvqU /[3
**FileAccess.java 57K1e~^
*//文件访问(定位，写) CSt6}_c!
package NetFox; 1V FAfv%}
import java.io.*; |PI.xl:ch
+:/`&LOS-
b[e+(X
public class FileAccessI implements Serializable{ JeWW~y`e?{
d!Y,i!l!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C\$7C5/
RandomAccessFile oSavedFile; IB(IiF5
long nPos; 9#O"^.Z !
"%,zB_ng\<
b:Rl }"a
public FileAccessI() throws IOException %#/7Tl:
{ nzhQ\'TC
this("",0); s8.oS);`
} YHvmo@
!6f#OAP\
B quyPG"
public FileAccessI(String sName,long nPos) throws IOException B:^5W{
{ {BJ[h
oSavedFile = new RandomAccessFile(sName,"rw"); dRWp/3 }
this.nPos = nPos; $sGX%u
oSavedFile.seek(nPos); axXAy5
} *!C^L"i
Vi5RkUY]
8$?a?7,>|
public synchronized int write(byte[] b,int nStart,int nLen) "=P@x|I
{ N{|N_}X`Y
int n = -1; He">kJx
try{ VdVca1Z
oSavedFile.write(b,nStart,nLen); ^hY<avi6s
n = nLen; u'Mq^8
} Xa9G;J$
catch(IOException e) e-UPu%'
{ zLf^O%zN
e.printStackTrace (); oE-i`;\8
} 9FcCq*D
9.vHnMcq
BO/2kL8*
return n; /SlCcozFL~
} IF5+&O
9R'rFI
\iu2rat^
} t)$>++i
PuUqWW'^
cN&b$8O=%
/* y$4,r4cmR|
**SiteInfoBean.java L.+5`&
*/ K V 4>(
package NetFox; Xps MgJ/w
bG2!5m4L
7v%~^l7:x
public class SiteInfoBean { G78rpp
l}:9)nXA{
~[ve?51
private String sSiteURL; //Site's URL cJi5\<b
private String sFilePath; //Saved File's Path //V?rs
private String sFileName; //Saved File's Name (nvSB}?
private int nSplitter; //Count of Splited Downloading File G^)|c<'M
/+02BP
|`:Uww+3
public SiteInfoBean() \$riwL
{//nSplitter的缺省值为5 O3Ks|%1
//default value of nSplitter is 5 (MJu3t @
this("","","",5); urXM}^
} ?\ho9nyK
|W\CV0L2
Vj~R6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I-fs*yzj;8
{ pX6OhwkTK
sSiteURL= sURL; auL?Hb
sFilePath = sPath; tao3Xr^?
sFileName = sName; /c3DltOdr
this.nSplitter = nSpiltter; ~~'XY(\L@
;uR8pz e
Yx XDRb\kW
} 78}iNGf
4s0>QD$J
^t9"!K
public String getSSiteURL() U/0NN>V
{ "QGP]F
return sSiteURL; fv<($[0
} f8'&(-
QJGRi
N \A)P
public void setSSiteURL(String value) 5vg@zH\z
{ ]7'Q2OU7
sSiteURL = value; }ndH|,
} I:AlM?
MJ&6 Z*
I?l*GO+pz
public String getSFilePath() >$HMZbsE
{ a/`fJY6rR
return sFilePath; 4.CLTy3W
} GD~3RnGQ{
hMi!H.EX.
f-4<W0%
public void setSFilePath(String value) T5W r;a
{ IxgnZX4N
sFilePath = value; K6!`b( v#
} BC!l)2
-D{~7&
1`B5pcuI
public String getSFileName() z\fD}`^8
{ |MTgKEsn
return sFileName; uR@\/6!@
} tty6
M(?|$$
.t7D/_
public void setSFileName(String value) HTkce,dQ
{ 6q6&N'We
sFileName = value; `=%[
} '<6Gz7O
'2:Ily,S@
}6m5MH$7q
public int getNSplitter() >nvreis
{ $0iz;!w
return nSplitter; !4I?59
} &<.Z4GxS
B]Yj"LM)
>:Q:+R;3o
public void setNSplitter(int nCount) s( 2=E|
{ |~v($c
nSplitter = nCount; j!:U*}f
} #@lr$^M
} -v>BeVF
E62VuX
,7/un8:%c
/* jwAO{.}T1r
**Utility.java gh i!4
*/ B:+}^=
package NetFox; }u:^Mz
q)<5&|V
"Z}0A/y
public class Utility { ukq9Cjs
R!}B^DVt
uyjZmT/-
public Utility() YJeZ{Wws
{ nGX~G^mZ
_Y\@{T;^Zb
vk;>#yoox
} !Me%W3
vaR0`F
//线程睡眠 ,ulNap"R
public static void sleep(int nSecond) &WvJg#f
{ '#u2q=n4*
try{ bis/Nfr]
Thread.sleep(nSecond); iWQBo>x
} 3S'V>:
catch(Exception e) R%3H"FU9w
{ |W*f6F3
e.printStackTrace (); !!Mp;h'}-
} #8nF8J<4
} 9OT2yCT
&\Cvrxa
//日志 EB@!?=0x
public static void log(String sMsg) a-i#?hld
{ Z4hP
System.err.println(sMsg); HzH_5kVW
} W,AIE6F
zL)S,
6@bGh|
public static void log(int sMsg) +u25>pX
{ z13"S(5D~
System.err.println(sMsg); s/P\w"/fN
} rYm<U!k
} !4.;Ftgjn
)m5<gp`
y<3v/,Y
/* G/<{:R"
**TestMethod.java /:awPYGH<1
*/ #c/v2
package NetFox; \4zvknk<
r]0o
*xL#1
public class TestMethod { r\=p.cw<
y7,~7f!N2
>]C;sP
public TestMethod() -!;vX @
{ ///xx/weblogic60b2_win.exe _;LHC;,:
try{ b2p<!?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DB?_E{y]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]V.9jlXF
SiteFileFetch fileFetch = new SiteFileFetch(bean); m{+lG*
fileFetch.start(); ax7 M
} Z.<1,EKi=
catch(Exception e){e.printStackTrace ();} z^B!-FcIz>
+H="5uO<
V!FzVl=G
} ]p0m6}B
2px5>4<
\ 0<e#0-V
public static void main(String[] args) %$sWNn
{ pR\etXeLd
new TestMethod(); \I'A:~b)L
} #+ n &
} }$AC0
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