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)); D(z}c,
} z8n=\xL
for(int i=0;i<nEndPos.length-1;i++) L5wrc4
{ szZ8-Y
nEndPos = nStartPos[i+1]; Ei$@)qS/
} *|OP>N
nEndPos[nEndPos.length-1] = nFileLength; /kK%}L_D
} ?H30
} 0q4E^}iR
n91@{U)QJ3
= nIl$9
//启动子线程 I4Y;9Gg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v"Z`#Bi
for(int i=0;i<nStartPos.length;i++) rzk]{W
{ Lt<KRs
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mW+QJ`3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Iz^lED
nStartPos,nEndPos,i); >U%:Nfo3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q.GA\o
fileSplitterFetch.start(); +DpiX&^h
} li`4&<WGC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^y1P~4w?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +CQ$-3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cW|M4`
nEndPos = " + nFileLength); 8Ev,9
// fileSplitterFetch[nPos.length-1].start(); [Y%H8}
@a[Y[FS
)9PP3"I
//等待子线程结束 eG F{.]
//int count = 0; 0}:wM':G
//是否结束while循环 u`j9m@`
boolean breakWhile = false; 8B|qNf `Yi
sy s6 V?
O=A(x m#
while(!bStop) %XUV[L}
{ Y, ?- []
write_nPos(); 0=,vdT
Utility.sleep(500); AVR=\ qR
breakWhile = true; DXH"`1[-
#&oL iz=hZ
wv6rjg:7
for(int i=0;i<nStartPos.length;i++) CSBk
{ )]W|i9
if(!fileSplitterFetch.bDownOver) G\I DgPj`
{ s/"l ?d
breakWhile = false; / }tMb
break; ^kF-mM=
} }2X"
} n>5/y c"/q
if(breakWhile) LY? `+/
break; H:x{qS4Si
ivi,/~L
X / {;
//count++; LYV\|a{Y
//if(count>4) 6Z,j^: B
// siteStop(); 5|pPzEA>
} %YhM?jMW
>h>
*fIb|r
System.err.println("文件下载结束！"); *It`<F|
} R{X@@t9@
catch(Exception e){e.printStackTrace ();} u*:;O\6l
} L6jD4ec8
n$})}kj
tu%!j}3s
//获得文件长度 $ M8ZF(W
public long getFileSize() qa!3lb_'M
{ `62iW3y
int nFileLength = -1; P_:~!+W,
try{ ":G\
URL url = new URL(siteInfoBean.getSSiteURL()); 'Drz6K_KrP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wQnW2)9!
httpConnection.setRequestProperty("User-Agent","NetFox"); LKx<hl$O
SD=kpf;
"'8^OZR
int responseCode=httpConnection.getResponseCode(); o/6'g)r*
if(responseCode>=400) e2@{Ab
{ i!U,qV1
processErrorCode(responseCode); x U1](O
return -2; //-2 represent access is error ux 7^PTgcO
} Te:4z@?
;hcOD4or
uv}?8$<\
String sHeader; -76l*=|
}0%~x,
oRbG6Vv/
for(int i=1;;i++) ,{tK{XpS
{ `RriVYc<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zt23on2
//Utility.log(in.readLine()); oU`J~6.&S
sHeader=httpConnection.getHeaderFieldKey(i); l^ Q-KUI
if(sHeader!=null) (C=.&',P
{ /Mg$t6vM
if(sHeader.equals("Content-Length")) h\@\*Xz<v
{ /%P|<[< [
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x_yQoae
break; D^Cpgha
} {okx*]PIc
} ?f{--|V
else p}r1@L s
break; R}S@u@mOE
} MzWVsV
} lebwGW,!
catch(IOException e){e.printStackTrace ();} ?df*Y5I2
catch(Exception e){e.printStackTrace ();} @'Y^A
s_j ?L
m,TN%*U!
Utility.log(nFileLength); $}*bZ~
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bIR&e E
return nFileLength; 1F*3K3T {
} ";PW#VHC
.*3.47O
}K8W%h<3S
//保存下载信息（文件指针位置） Wvg+5Q
private void write_nPos() }ob&d.XZ
{ .w .`1 g
try{ S*5hO) C
output = new DataOutputStream(new FileOutputStream(tmpFile)); bJ$6[H-:
output.writeInt(nStartPos.length); oXQzCjX_
for(int i=0;i<nStartPos.length;i++) R'#1|eWCa
{ cU+%zk
// output.writeLong(nPos); iFypKpHg~
output.writeLong(fileSplitterFetch.nStartPos); hS?pc<~`#
output.writeLong(fileSplitterFetch.nEndPos); ks}J ke>
} d5hYOhO[
output.close(); &m8#^]*
} [#}0)
catch(IOException e){e.printStackTrace ();} G1vg2'A
catch(Exception e){e.printStackTrace ();} FM80F_G^z
} )$.::[pNA
.d4L@{V
9;L5#/E
//读取保存的下载信息（文件指针位置） fs:%L
private void read_nPos() \9Z1'W
{ pr;z>|FgA>
try{ &N`s@Ka
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); a___SYl 'K
int nCount = input.readInt(); \fk%^1XY
nStartPos = new long[nCount]; 91Fx0(
nEndPos = new long[nCount]; ;E!(W=]*F
for(int i=0;i<nStartPos.length;i++) >l!#_a
{ ++HHUM
nStartPos = input.readLong(); \Y4>_Mk
nEndPos = input.readLong(); 3 W%Bsqn
} $CXMeY{tOo
input.close(); `[&) X
} EINjI:/D
catch(IOException e){e.printStackTrace ();} hI^Hqv
catch(Exception e){e.printStackTrace ();} ^uDNArDmj5
} -_p+4tV
h W<fu
C`++r>
private void processErrorCode(int nErrorCode) _gGI&0(VM
{ I"4Lma
System.err.println("Error Code : " + nErrorCode); f4h|Nn%;
} 2NNAsr}L
hJ>Kfm
p H5iv>H
//停止文件下载 N 9.$--X}D
public void siteStop() 1;U `e4"
{ ;?*`WB
bStop = true; =Fd!wkB'{
for(int i=0;i<nStartPos.length;i++) GW29Rj1
fileSplitterFetch.splitterStop(); >R9_;
Zs(I]^w;d
g}vOp3^
} `2B,+ytW8
} )}G?^rDH(
//负责部分文件的抓取 sM4Qu./
**FileSplitterFetch.java {1<XOp#b
*/ n0nvp@?7bJ
package NetFox; @jKiE%OP
J#```cB
5)T=^"IHXi
import java.io.*; |9Gng`)
import java.net.*; &V$qIvN$
o/;kzi
o~_wx
public class FileSplitterFetch extends Thread { B;3lF;3`
sy ]k
u(Y! _
String sURL; //File URL 0L ^WTq
long nStartPos; //File Snippet Start Position &yQilyU{V
long nEndPos; //File Snippet End Position pZYcCc>6&
int nThreadID; //Thread's ID {N \ri{|
boolean bDownOver = false; //Downing is over 9(\eL9^
boolean bStop = false; //Stop identical yX {CV7%O
FileAccessI fileAccessI = null; //File Access interface j/oM^IY
=u*\P!$
.[@TC@W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }k`-n32)|
{ *tWZ.I<<
this.sURL = sURL; Y`O"+Jr
this.nStartPos = nStart; |#&{`3$CG[
this.nEndPos = nEnd; d~G, *
nThreadID = id; /|kR= ~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p}b:(QN~m
} ,t2yw
&gDwsW
Ew&pwsQ
public void run() $,mljJSQv
{ GH6HdZ
while(nStartPos < nEndPos && !bStop) 4;rt|X77
{ FnoE\2}9
_7)>/YK?}4
q{fgsc8v\
try{ 3?R56$-+
URL url = new URL(sURL); ?yfw3s
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d(=*@epjR
httpConnection.setRequestProperty("User-Agent","NetFox"); s>RtCw3,
String sProperty = "bytes="+nStartPos+"-"; i gyTvt!
httpConnection.setRequestProperty("RANGE",sProperty); /M0A9ZT[
Utility.log(sProperty); pG|+\k/B
8)NQt$lWp
hS( )OY
InputStream input = httpConnection.getInputStream(); cl`!A2F1G#
//logResponseHead(httpConnection); @hb K
E#0_y4
*VbB'u:
byte[] b = new byte[1024]; o\#C#NiT
int nRead; jMpV c E#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hv>16W$_
{ ;Nd,K C0k
nStartPos += fileAccessI.write(b,0,nRead); <\9M+
//if(nThreadID == 1) =SY`Xkj[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S4salpz
} h@^d Vg
kn^?.^dVX
~!PaBS3A
Utility.log("Thread " + nThreadID + " is over!"); 8iB}gHe9
bDownOver = true; $*KM%M6
//nPos = fileAccessI.write (b,0,nRead); M9t`w-@_w
} w@jC#E\
catch(Exception e){e.printStackTrace ();} 4P>4d +
} `veq/!
} \qo}}I>e
mBQp#-1\
y|+n77[Gv
//打印回应的头信息 cl'#nLPz;
public void logResponseHead(HttpURLConnection con) (FY<%.Pa
{ d:_3V rRZ
for(int i=1;;i++) ]y**ZFA
{ a%IJ8t+mn
String header=con.getHeaderFieldKey(i); k>'c4ay290
if(header!=null) /Cl=;^)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #guq/g$
Utility.log(header+" : "+con.getHeaderField(header)); HgY>M`U
else J/{!_M-
break; [%1 87dz:D
} M?nYplC
} ; *@lH%u
qGYru1
(c'kZ9&
public void splitterStop() oA;> z
{ &3:U&}I
bStop = true; "lT>V)NB'
} KJLC2,
k/`WfSM\.
;LhNz()b
} pAY[XN
S*D Bzl
1%^d<%,]
/* ^gu;
**FileAccess.java h=7eOK]
*//文件访问(定位，写) 0\X'a}8Bu
package NetFox; DH*=IzcJf
import java.io.*; -IP3I
$YPQi.
)Z.M(P
public class FileAccessI implements Serializable{ vrr`^UB2
)yyS59s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1f/8XxTB
RandomAccessFile oSavedFile; qbunP!
long nPos; gT=RJB
d=$1Z.]
]ICBNJ
public FileAccessI() throws IOException z"*$ .
{ .%3qzOrN
this("",0); &l| :1
} -AX[vTB
E~| XY9U36
d$O)k+j
public FileAccessI(String sName,long nPos) throws IOException }8\"oA6
{ Ze:Y"49S+>
oSavedFile = new RandomAccessFile(sName,"rw"); (+=TKI<=
this.nPos = nPos; C\d5t4s
oSavedFile.seek(nPos); !P"=57d}"l
} y~jYGN
mm@)uV<\
gL-\@4\wc
public synchronized int write(byte[] b,int nStart,int nLen) puPYM"
{ j1hx{P'
int n = -1; S$egsK"~
try{ :87HXz6]jS
oSavedFile.write(b,nStart,nLen); ?->&)oAh
n = nLen; 5%Xny8 ]|D
} FhyA_U%/nF
catch(IOException e) qt !T%K
{ U(t_uc5q
e.printStackTrace (); 4t<l9Ilp
} %w0Vf$
U}]uPvu
<s737Rl
return n; MGGc
} nRL2Z5iO-
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_);;@T
} F]"Hs>
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Ue8k9%qV
/* Nsd7?|@HI
**SiteInfoBean.java ji(Y?vhQt
*/ _H(:$=$Q
package NetFox; dAZh# i[
,svj(HP$
O(Tdn;1
public class SiteInfoBean { '+Gy)@c
nYv`{0S+m
1hT!~'
private String sSiteURL; //Site's URL z12c9k%s
private String sFilePath; //Saved File's Path E+.%9EKU
private String sFileName; //Saved File's Name J|Xu]fg0
private int nSplitter; //Count of Splited Downloading File tHj |_t
5%5z@Ka
^:yg,cS|Be
public SiteInfoBean() ~{O9dEI
{//nSplitter的缺省值为5 D#~S<>u@
//default value of nSplitter is 5 tUp'cG
this("","","",5); xg>AW Q
} 0qV"R7TW
NSPa3NE
I9 R\)3"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `iiZ
{ .$k2.-k
sSiteURL= sURL; =:!$'q:
sFilePath = sPath; =R>%}5
sFileName = sName; qU1^ K
this.nSplitter = nSpiltter; \"r*wae
WG_20JdJY
A|D]e)/6+B
} 9_6.%qj&
zP|y3`.52
@"`{gdB$
public String getSSiteURL() ZL-YoMHc+_
{ Y\qiYra
return sSiteURL; ?8d7/KZO
} 5G\CT&cQR
CulU?-[i
iE|qU_2Y
public void setSSiteURL(String value) U~mv1V^.
{ Cyb-}l
sSiteURL = value; vlD!YNy
} yvgn}F{}
g*NKY`,
?Q`Sx
public String getSFilePath() M=n_;3,o
{ ohdWEU,
return sFilePath; ,=9e]pQ
} l#FW#`f
&?@gUk74"
hm%'k~
public void setSFilePath(String value) GnE%C2L-
{ #nE%.k|R~
sFilePath = value; fwojFS.K
} 3sk$B%a>Z
m\h/D7zg
s_=/p5\
public String getSFileName() u7=jtB
{ ?Jlz{msI
return sFileName; .qyk[O
} -}lcMZY
-$(,&qyk
1@nGD<,.
public void setSFileName(String value) _jw A_
{ ) 0x*>;"o
sFileName = value; LF'M!C9|
} web=AQ5I4
U}xQUFT|
62B` Z5j#
public int getNSplitter() E6SGK,f0D
{ Ojkbv
return nSplitter; +e0]Y8J{
} YC:>)
4]N`pD5
Ve,_;<F]S
public void setNSplitter(int nCount) G .~Psw#
{ uf*sI
nSplitter = nCount; R|T_9/#)
} _/"m0/,
} vgzNT4o
Y8I$JBO
ui4H(A'}
/* {m9OgR5U
**Utility.java D-.XSIEMu
*/ =KwG;25hX
package NetFox; +[9~ta|j
G3P3
(=${@=!z
public class Utility { J{=by]-rD,
cO2 .gQo'
hu-fwBK
public Utility() Hw34wQX
{ n 5NkjhP~Z
S @\Pki+n[
$|!VP'VI
} `LL#Aia
8#S|jBV
//线程睡眠 b1>%%#
public static void sleep(int nSecond) xtKWh`[&
{ MpM-xz~
try{ /4j'?hB<g
Thread.sleep(nSecond); HoGrvt<:.P
} }U'fPYYi8
catch(Exception e) L<Q1acoZm
{ )'M<q,@<(
e.printStackTrace (); *J@2A)ZDv0
} %;9f$:U
} DY?`Y%"
6}2vn5 E//
//日志 %"j<`
public static void log(String sMsg) pL>Q'{7s3
{ zt!mx{l'
System.err.println(sMsg); Y_S^B)y
} b&p*IyJR
'OSZ'F3PV
Z=DAA+T`
public static void log(int sMsg) DqrS5!C
{ DM{7x77
System.err.println(sMsg); MuYr?1<q
} V{;Mh u`+
} ?)-*&1cv
Afo(! v
z?_c:]D
/* ^-PlTmT
**TestMethod.java p+#J;.
*/ +"Ek? )?
package NetFox; e2;19bj&
$zbm!._~DA
25*/]iu
public class TestMethod { =(K;z9OR
tTe\#o`
EbuOPa
public TestMethod() \TkBV?W
{ ///xx/weblogic60b2_win.exe `4}zB#3
try{ )!hDF9O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fXvJ3w(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Fe%Q8RIh_
SiteFileFetch fileFetch = new SiteFileFetch(bean); TZi%,yK
fileFetch.start(); Y(78qs1w
} ;2@MPx
catch(Exception e){e.printStackTrace ();} [Nr6qxWg
}3j/%oN.(
q0jzng
} G+ Y`65
Erl"X}P
.@JXV $Z
public static void main(String[] args) U:c!9uhp
{ l~AmHw e
new TestMethod(); \=v7'Hp
} R0_%M
} ;n00kel$
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