http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); ?r'2GR2Sk4
} h@{mcz
for(int i=0;i<nEndPos.length-1;i++) g}OZ!mKd
{ 1!=^mu8
nEndPos = nStartPos[i+1]; 6bwzNY 7
} Bln($lOz
nEndPos[nEndPos.length-1] = nFileLength; v,d bto0
} @OGHS}-\
} N\t( rp
t)l
IZs NMY
//启动子线程 T^DJ/uhd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m#,AD,s
for(int i=0;i<nStartPos.length;i++) \|YIuzlO4
{ :V!F~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M-V{(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \\)9QP?
nStartPos,nEndPos,i); >3?p23|;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I/hq8v~S
fileSplitterFetch.start(); !zQbF&>
} hd1aNaF-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l2ARM3"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +pY--5t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tyU'[LF?
nEndPos = " + nFileLength); ?p'DgL{
// fileSplitterFetch[nPos.length-1].start(); w(oi6kg
})yB2Q0
gLK_b;:
//等待子线程结束 ?J,K[.z
//int count = 0; oe*CZ
//是否结束while循环 P[%nD cB
boolean breakWhile = false; REGk2t.L
LEC=@) B
I&9Itn p$
while(!bStop) '\% Kd+k
{ E}g)q;0v|2
write_nPos(); Q;?rqi ,
Utility.sleep(500); y#{v\h Cz
breakWhile = true; _KJ!C!
n+57# pS7
NHQi_U
for(int i=0;i<nStartPos.length;i++) rK[;wD<
{ tUk)S
if(!fileSplitterFetch.bDownOver) b!JrdJO,DP
{ dT7!+)s5-
breakWhile = false; ;R([w4[~
break; 3_ ZlZ_Tq
} [tk6Kx8a
} M.9w_bW]#D
if(breakWhile) cBtQ2,<6
break; uI\6":/u
WXQ+`OH7
%+iAL<S
//count++; \YPvpUg
//if(count>4) _P9*78
// siteStop(); <!q_C5>XJ
} oV'G67W
57Bxx__S4`
JqV}>"WMV
System.err.println("文件下载结束！"); fb8)jd'~}O
} !;Vqs/E
catch(Exception e){e.printStackTrace ();} X?.tj Z,
} w/e?K4
x c|1?AFj
E5yn,-GyE0
//获得文件长度 J^-a@'`+
public long getFileSize() 8`z
{ DJb9] ,=a
int nFileLength = -1; # TZ`
try{ o]DYS,v
URL url = new URL(siteInfoBean.getSSiteURL()); 30W.ks5(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WOQ>]Z
httpConnection.setRequestProperty("User-Agent","NetFox"); E?FUr?-[
*)L~1;7j>
gu"@*,hL
int responseCode=httpConnection.getResponseCode(); yRR[M@Y
if(responseCode>=400) 9v/=o`J#
{ )|6OPR@(#/
processErrorCode(responseCode); H.< F6
return -2; //-2 represent access is error @RHG@{x{K
} ~3)d?{5
H 3so&_
"(mF5BE-E
String sHeader; p,BoiYdi
tYp 185
u\(>a
for(int i=1;;i++) Gkm{b[
{ W~FU!C?]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *|ef#-|D
//Utility.log(in.readLine()); 1&RB=7.h
sHeader=httpConnection.getHeaderFieldKey(i); Vqr]Ui
if(sHeader!=null) ar_@"+tZ
{ jLn|zK
if(sHeader.equals("Content-Length")) !JtM`x/yR
{ B,] AfH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3oV2Ek<d
break; 3+&k{UZjt
} t +|t/1s2
} &F8*>F^7
else v]#[bqB.b
break; 2({|LQqk
} n~ZZX={a
} <}G/x*N
catch(IOException e){e.printStackTrace ();} rv c%[HfW;
catch(Exception e){e.printStackTrace ();} 1DlXsup&?#
=7[}:haB{
Zb&"W]HSf
Utility.log(nFileLength); zt!7aVm n
^VEaOKMr
V -_MwII-
return nFileLength; $o/i / wcj
} ~])Q[/=p
;I*N%a TK
MDBqIL]Hc
//保存下载信息（文件指针位置） ~~@dbB
private void write_nPos() _WZ{i,
{ sR^b_/ElxT
try{ t'Zv)Wu1E
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]Upr<!
output.writeInt(nStartPos.length); vl~HV8MAv
for(int i=0;i<nStartPos.length;i++) UW1i%u k
{ 51-'*Y
// output.writeLong(nPos); }0sLeGJ!
output.writeLong(fileSplitterFetch.nStartPos); 5"ooam3
output.writeLong(fileSplitterFetch.nEndPos); y&/bp<Z
} MnlD87x@X
output.close(); b~2LD3"3
} 6z]y =J
catch(IOException e){e.printStackTrace ();} _sn<"B%>
catch(Exception e){e.printStackTrace ();} jO9!:L>b`
} nNeCi
,~/WYw<o
_ ^'QHWP
//读取保存的下载信息（文件指针位置） ilyF1=bp
private void read_nPos() ?_r{G7|D
{ G7i0P j
try{ N)PkE>%X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); KWM.e1(
int nCount = input.readInt(); .<Ays?
nStartPos = new long[nCount]; ?vFtv}@\
nEndPos = new long[nCount]; eaDR-g"
for(int i=0;i<nStartPos.length;i++) <{h\Msx%
{ eJ6 #x$I,
nStartPos = input.readLong(); >f4[OBc
nEndPos = input.readLong(); i(;.Y
} 6uTC2ka[&R
input.close(); %`~+^{Wp
} x4h.WDT$
catch(IOException e){e.printStackTrace ();} G9Noch9 g
catch(Exception e){e.printStackTrace ();} 4Dy1M}7
} @R<z=n"
W.%p{wB|
8llXpe
private void processErrorCode(int nErrorCode) NwdrJw9
{ >I-rsw2
System.err.println("Error Code : " + nErrorCode); &3J^z7kU
} {jv+ JL"5
ohs`[U=%~
fg lN_
//停止文件下载 ox_DEg7l
public void siteStop() R"l6|9tmP
{ B_D0yhh
bStop = true; zeq")A
for(int i=0;i<nStartPos.length;i++) @n=&muC}
fileSplitterFetch.splitterStop(); vvs2:87zvJ
6=qC/1,l
X{(?p=]
} MPKrr
} )a5ON8?
//负责部分文件的抓取 y4r?M8]"r
**FileSplitterFetch.java (5CgC<
*/ =>kg]
package NetFox; io(!z-$
aXzb]">
vxug>2
import java.io.*; =qbN?a/?2
import java.net.*; VFMn"bYOB
'p78^4'PL
)Gk?x$pY@
public class FileSplitterFetch extends Thread { vexF|'!}0#
EZzR"W/
f*ABIm
String sURL; //File URL mU
long nStartPos; //File Snippet Start Position 3ZI:EZ5
long nEndPos; //File Snippet End Position cNN0-<#c
int nThreadID; //Thread's ID fUfd5W1"
boolean bDownOver = false; //Downing is over aOd|;Z
boolean bStop = false; //Stop identical KJv%t_4'F
FileAccessI fileAccessI = null; //File Access interface `(gQw~|z
cK2;)&U7
Ux{0)"fj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3)L#V .
{ +>%51#2.Q
this.sURL = sURL; 8'_MCx(
this.nStartPos = nStart; ;(jL`L F
this.nEndPos = nEnd; =v'Aub
nThreadID = id; q317~z_nl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 M,X)rM}Q
} }_F:]lI*R
hW9!
d[5v A/8O
public void run() [La}h2gz
{ D?8(n=#[
while(nStartPos < nEndPos && !bStop) _ker,;{9C
{ zY7M]Az
Q`NdsS2
:WsHP\r
try{ /Oi(5?Jn
URL url = new URL(sURL); Z{:;LC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RZKx!X4=q
httpConnection.setRequestProperty("User-Agent","NetFox"); s$,G5Feub
String sProperty = "bytes="+nStartPos+"-"; PIXqd,
httpConnection.setRequestProperty("RANGE",sProperty); 4mKH |\g
Utility.log(sProperty); `rK@> -
CE!cZZ
>,tJq%
InputStream input = httpConnection.getInputStream(); bfEH>pQ>#
//logResponseHead(httpConnection); $7]?P;$
U;*t5l
sDR Av%w
byte[] b = new byte[1024]; YJ-<t6
int nRead; + !"YC
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .C5<uW5-R
{ 7[uN;B#V
nStartPos += fileAccessI.write(b,0,nRead); 'r ^.Ao5
//if(nThreadID == 1) w{lj'3z I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :-lq Yd5^
} DU)q]'[u
m/jyc# L:u
%'=2Jy6h
Utility.log("Thread " + nThreadID + " is over!"); "KS"[i!3j
bDownOver = true; 7'65+c[&
//nPos = fileAccessI.write (b,0,nRead); gmn b
} evD=]iVD
catch(Exception e){e.printStackTrace ();} !syyOfu`}
} fAz4>_4
} NFtA2EMLu[
MK@rx6<9
jJNl{nyq
//打印回应的头信息 3TLym&
public void logResponseHead(HttpURLConnection con) J]zhwM
{ o8H\l\(
for(int i=1;;i++) 98| v.d
{ FGie*t
String header=con.getHeaderFieldKey(i); >R_m@$`
if(header!=null) \ykA7Y%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6d6Dk>(V
Utility.log(header+" : "+con.getHeaderField(header)); K7.ayM 0
else 3-6MGL9
break; [` }w7
} PFx.uqp
} f Ayh9
iOCs%J
;K|K]c
public void splitterStop() f2pA+j5[
{ ^c/3!"wK
bStop = true; <gGO
} S.`hl/
z C$F@
t9*e"QH
} t^>P,%$
"PWGtM:L8Y
-P-8D6
/* 0u&x%c
**FileAccess.java nUVk;0at
*//文件访问(定位，写) w-$iKtb.
package NetFox; (x@J@ GP*
import java.io.*; TuPD5-wB&
F|/6;&*?M
~`^kP.()
public class FileAccessI implements Serializable{ BB9eQ: xO
$cuBd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1{]S[\F]
RandomAccessFile oSavedFile; \CE+P5
long nPos; R.l!KIq
0%;| B
UWhHzLcXh
public FileAccessI() throws IOException !FyO5`v
{ PX0N7L
this("",0); 1:- M<=J?f
} J7oj@Or9
]B8iQr-!
}.U(Gxu$
public FileAccessI(String sName,long nPos) throws IOException OC-d5P
{ CS*lk!C
oSavedFile = new RandomAccessFile(sName,"rw"); [`E_/95
this.nPos = nPos; [McHl1a
oSavedFile.seek(nPos); H^`J(J+
} ])bgUH
#Tag"b`
f\=,_AQ
public synchronized int write(byte[] b,int nStart,int nLen) ZAeJTCCk
{ ]9'F<T= $_
int n = -1; N+5f.c+S-
try{ {R[V
oSavedFile.write(b,nStart,nLen); RhT:]
n = nLen; =h=-&DSA
} `1Md1e:J
catch(IOException e) sh0x<_
{ Q%!xw(
e.printStackTrace (); 7<(U`9W/q
} {M=B5-
B-L@ 0gH
Q>;Aq!mr=
return n; W>Pcj EI
} 4T"L#o1
r8N)]HsZH
)ezkp%I5D
} 5 ';[|f
;9fWxH
EV* |\ te
/* -iW>T5f
**SiteInfoBean.java S;iD~>KP
*/ !B{(EL=g
package NetFox; qC& xuu|
4DP<)KX
OI:=>Bk
public class SiteInfoBean { 0$Zh4Y
)@y'$)5s
&gC)%*I4
private String sSiteURL; //Site's URL @m:' L7+
private String sFilePath; //Saved File's Path <&B]p
private String sFileName; //Saved File's Name N!v>2"x8q
private int nSplitter; //Count of Splited Downloading File [AD%8H
#a9R3-aP
\>w 2D
public SiteInfoBean() <; Td8O89_
{//nSplitter的缺省值为5 ?;(!(<{
//default value of nSplitter is 5 x2l}$(7
this("","","",5); N>P" $
} f4dHOH
prIJjy-F
Oq3t-omXS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !^1oH**
{ @^-f+o
sSiteURL= sURL; %4#ChlXB
sFilePath = sPath; ntL%&wY
sFileName = sName; Q'ib7R;V,
this.nSplitter = nSpiltter; Zw/??Tq b
K7(GdKZe
eISHV.QV
} MC B2
_jxysFl=
sv "GX<+
public String getSSiteURL() g&ba]?[A
{ ^Ga_wJP8S
return sSiteURL; TC:t!:
} 4zBcq<R7
;t@^Z_z,CR
Tn38]UL
public void setSSiteURL(String value) %F;uW[4r
{ (15.?9
sSiteURL = value; NB( GE
} '$ G%HUn
9N) Ea:N
V|nJ%G\
public String getSFilePath() )^E6VD&6
{ %6@m~;c0
return sFilePath; pf=CP%L
} {gDoktC@M
^*~4[?]S
*iPBpEWC
public void setSFilePath(String value) d+8|aS<A
{ [t5Dd
sFilePath = value; L>57eF)7
} g^\>hjNX
2Myz[)<P_
oOQ0f |MGp
public String getSFileName() ]ddL'>$c$
{ L'>0E(D
return sFileName; ^c sOXP=Yp
} 8Y;>3zth7
,/Y$%.Rp
_9iF`Q
public void setSFileName(String value) ]U 1S?p
{ +gb"} cN
sFileName = value; &23t/`
} l~*d0E-$
M3)Id?|]6
oYeFOw`
public int getNSplitter() lJ4/bL2I/
{ lstnxi%x
return nSplitter; >LEp EMJ\
} S?~/ V]
7{f{SIB
(*!4O>]
public void setNSplitter(int nCount) qKuHd~M{ 1
{ $I\lJ8
nSplitter = nCount; <>=abgg
} twPD'X!r
} TiI3<.a!
.ldBl
(i^<er q
/* k,[[ CZ0j
**Utility.java FWyfFCK
*/ #~qY%X
package NetFox; 9z?B@;lMc
FzFP 0
FOX0
public class Utility { gAy"W$F
DEKO]i
8uetv
public Utility() ,aSK L1
{ sRGIHT#
V"sm+0J
5U JMiwP{
} <d3N2
(_~Dyvo
//线程睡眠 "eKM<S
public static void sleep(int nSecond) BH?fFe&J:`
{ K%>3ev=y.s
try{ 1f5;^T I
Thread.sleep(nSecond); th|TwD&mO
} ebB8.(k9G3
catch(Exception e) 0J9Ub
{ YoRD9M~iG~
e.printStackTrace (); G/}nwj\
} K6oQx)|
} A)o%\j
f<2<8xS
//日志 o}lA\A
public static void log(String sMsg) T:EUI]
{ 0]t7(P"F6
System.err.println(sMsg); JuXuS
} dw< b}2
!tv+,l&L
0[SrRpD
public static void log(int sMsg) BQ77n2(@
{ tumYZ)nW
System.err.println(sMsg); i.>d#S
} 17;qJ_T)
} 4ew#@
v@]\ P<E
:.NCS`z_
/* hc5iIJ]
**TestMethod.java AU H_~SY
*/ H-Or
package NetFox; UNKXfe(X9
5B+I\f&
W q>qso
public class TestMethod { -VRKQNT
$t42?Z=N&z
eop7=!`-~~
public TestMethod() C2Af$7c
{ ///xx/weblogic60b2_win.exe 6ALUd^
try{ AG<TY<nqL
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \"hP*DJ"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); r#'E;Yx
SiteFileFetch fileFetch = new SiteFileFetch(bean); Fpf-Fa-K\b
fileFetch.start(); .ID9Xd$fky
} W2j@Q=YDS
catch(Exception e){e.printStackTrace ();} C*,PH!$k
_8nT$!\\
+h?z7ZY^
} _f~m&="T!
e.pq6D5
i?pC[Ao-_
public static void main(String[] args) g|V0[Hnq6
{ YXjWk),
new TestMethod(); TP&&' 4?D1
} 5iP{)
} !V;glx[
点击下载更多相关资料