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)); 6Xn9$C)
} ,t*H: *
for(int i=0;i<nEndPos.length-1;i++) >~'z%
{ }Q^*Zq9-
nEndPos = nStartPos[i+1]; "2tKh!?Q
} pI_:3D xe
nEndPos[nEndPos.length-1] = nFileLength; )RWY("SUy1
} ?oV|.LM:W
} _Wp.s]D [
7pyaHe
6!Mm")
//启动子线程 qd'Z|'j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ts,V+cEA
for(int i=0;i<nStartPos.length;i++) VHLNJnA
{ Hh&qjf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Osy_C<O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), JPZH%#E(
nStartPos,nEndPos,i); ra@CouR^c{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B oiS
fileSplitterFetch.start(); CLuQ=-[|
} :S-{a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #B!M,TWf9s
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k2#|^N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wT,=C'
nEndPos = " + nFileLength); (*T$:/zIS
// fileSplitterFetch[nPos.length-1].start(); 2P=~6(
L{XW2c$h
[{>1wJ Pdj
//等待子线程结束 alsD TQ'
//int count = 0; ^oE#;aS
//是否结束while循环 u2[L^]|
boolean breakWhile = false; d+ [2Sm(7
ZC^NhgX
uA t{WDHm
while(!bStop) _ib @<%
{ d*U<Ww^q
write_nPos(); Ue>{n{H"y
Utility.sleep(500); #D ]CuSi
breakWhile = true; 6y^GMlsI
{lppv(U
U+["b-c
for(int i=0;i<nStartPos.length;i++) >4+KEK
{ h$6~3^g:P
if(!fileSplitterFetch.bDownOver) lO0}
{ Jy('tfAHp
breakWhile = false; I_R6 M1
break; ;Z`R!
} Pj!f^MN
} P%!=Rj^2m
if(breakWhile) rrphOG
break; LEX @hkh
vbG&F.P
43O5|8o
//count++; 2,|;qFJY-@
//if(count>4) ID{XZ
// siteStop(); Tgbq4xR(
} -]n%+,3L
3kwkU
W|s";EAM
System.err.println("文件下载结束！"); }EJ/H3<
} i;29*"
catch(Exception e){e.printStackTrace ();} hR.vJ2oa
} zW)Wt.svP
RU>qj *e
@Q;s[Kg{!
//获得文件长度 !*?9n^PaF
public long getFileSize() @tJic|)x
{ vF[ 4kDHk
int nFileLength = -1; 8f65;lyN
try{ h b8L[ 4
URL url = new URL(siteInfoBean.getSSiteURL()); y3PrLBTz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {9^p3Q+:P
httpConnection.setRequestProperty("User-Agent","NetFox"); ,^DP
B^ddi
A<(DYd1H
int responseCode=httpConnection.getResponseCode(); =([4pG
if(responseCode>=400) dt"&
{ _,d<9 Y)
processErrorCode(responseCode); &rl;+QS
return -2; //-2 represent access is error roBb8M|q
} $3%+N|L
hMV>5Y[s
+F2X2e)g"
String sHeader; |y+_BZ5
x]3[0K5;
~-R2mAUK
for(int i=1;;i++) K{B|
{ 8N3y(y0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rI6+St
//Utility.log(in.readLine()); p(Osz7K
sHeader=httpConnection.getHeaderFieldKey(i); qL[SwEc
if(sHeader!=null) Mq'm TM
{ l@-h.tS
if(sHeader.equals("Content-Length")) (=EDqAZg
{ f/iMI)J
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ibG>|hV
break; Z/|=@gpw
} @g]EY&Uzl
} 8.+ yZTg
else :fq4oHA#
break; I`i"*z
} t*u#4I1
} }Gy M<!:
catch(IOException e){e.printStackTrace ();} XP?)xDr8
catch(Exception e){e.printStackTrace ();} )OVa7[-T
(XY`1|])`
1EWZA
Utility.log(nFileLength); PrA(==FX/
Xkg
Gzg3{fXl
return nFileLength; !ab ef.%:
} i$<")q
(Nv-wU
;Me*#/
//保存下载信息（文件指针位置） ;K%/sIIke
private void write_nPos() 5Z6MQ`(k
{ {t!7r_hj
try{ %/5Wj_|p
output = new DataOutputStream(new FileOutputStream(tmpFile)); NK(_ &.F
output.writeInt(nStartPos.length); M CP GDr
for(int i=0;i<nStartPos.length;i++) y\Utm$)j
{ ()F{kM8
// output.writeLong(nPos); 1xkrhqq
output.writeLong(fileSplitterFetch.nStartPos); DH.UJ+
output.writeLong(fileSplitterFetch.nEndPos); W8;!rFW
} B;W%P.<.
output.close(); Jyr V2Tk^
} +lhCF*@*N
catch(IOException e){e.printStackTrace ();} %H2ios[UO
catch(Exception e){e.printStackTrace ();} qd#7A ksm
} ,VSO;:Z
c"pOi&
5Dz$_2oM3
//读取保存的下载信息（文件指针位置） 9cU9'r# h
private void read_nPos() Bx#=$ka
{ \<09.q<8
try{ `Pc<0*`a
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GNq f
int nCount = input.readInt(); bovAFdHW
nStartPos = new long[nCount]; L[,19;(
nEndPos = new long[nCount]; CjP<'0gT
for(int i=0;i<nStartPos.length;i++) r@bh,U$
{ $bFK2yx?=
nStartPos = input.readLong(); zNdkwj p+
nEndPos = input.readLong(); ASre@pW
} kfT*G +l]
input.close(); s(J>yd=
} oD1k7Gq1
catch(IOException e){e.printStackTrace ();} Xc}XRKiy{
catch(Exception e){e.printStackTrace ();} 1?1Bz?EKF*
} 8N?D1;F;
0y?;o*&U\
pRL:,q\
private void processErrorCode(int nErrorCode) gZ7R^] k
{ UxzF5V5
System.err.println("Error Code : " + nErrorCode); 2Q5@2jT
} bv b\G
z ynu0X
G9yK/g&q
//停止文件下载 KAI2[ gs
public void siteStop() j%^4 1y
{ Y?3tf0t/
bStop = true; ahy6a,)K~
for(int i=0;i<nStartPos.length;i++) 8T6NG!/
fileSplitterFetch.splitterStop(); |%mZ|,[
?+.C@_QZQ
2zW IB[
} s&-MJ05y
} aekke//y
//负责部分文件的抓取 *kg->J
**FileSplitterFetch.java ?+^p$'5
*/ a.}#nSYP
package NetFox; M*kE |q/K
0doJF@H
UeLO`Ug0;
import java.io.*; QuPz'Ut#
import java.net.*; /lu|FWbEw
>7%T%2N
G8klWZAJ
public class FileSplitterFetch extends Thread { V-n{=8s
zqXF`MAB=
m m`#v g,
String sURL; //File URL \AKP ea=
long nStartPos; //File Snippet Start Position ||awNSt
long nEndPos; //File Snippet End Position bvB',yBZ
int nThreadID; //Thread's ID =\5WYC
boolean bDownOver = false; //Downing is over G[yzi
boolean bStop = false; //Stop identical z+{qQ!
FileAccessI fileAccessI = null; //File Access interface fx[&"$X
orH6R8P]
tm^joK[{|J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZL\^J8PRK
{ o,dp{+({
this.sURL = sURL; 9&AO
this.nStartPos = nStart; ,)#rD9ZnC
this.nEndPos = nEnd; MK)}zjw
nThreadID = id; 1BU97!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >19s:+
} \\#D!q*
UGy3B)
to</
public void run() ,.>9$(s
{ h%ys::\zF
while(nStartPos < nEndPos && !bStop) WcNQF!f
{ dB0#EJaE
PENB5+1OK
!V3+(o1
try{ L%is"NZh
URL url = new URL(sURL); d$3md<lIB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >{tn2Fkg>
httpConnection.setRequestProperty("User-Agent","NetFox"); cOX)+53
String sProperty = "bytes="+nStartPos+"-"; wTU$jd1;+
httpConnection.setRequestProperty("RANGE",sProperty); sIgTSdk
Utility.log(sProperty); ]B=*p0~j^n
T:X*
u@#%SX
InputStream input = httpConnection.getInputStream(); aq}hlA(w
//logResponseHead(httpConnection); uH%b rbrU
PR:B6 F8
A+* lV*@0
byte[] b = new byte[1024]; L,y q=%h|
int nRead; 8xgBNQdPT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $Z#~wsw
{ }%/mPbd#
nStartPos += fileAccessI.write(b,0,nRead); 8:V,>PH
//if(nThreadID == 1) _uMG?Sbx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N'WTIM3W
} klT?h[I!
`D~oY=
l_Lz9k
Utility.log("Thread " + nThreadID + " is over!"); *af\U3kx
bDownOver = true; G&{yM2:E
//nPos = fileAccessI.write (b,0,nRead); p7;K] AW
} {\`ttc>
catch(Exception e){e.printStackTrace ();} D!,5j_,j%
} K}re{y
} |kPgXq6
|7c],SHm
-(:T&rfTp
//打印回应的头信息 z@~H{glo
public void logResponseHead(HttpURLConnection con) _.; PLq~0
{ Yp;Z+!!UZ
for(int i=1;;i++) scH61Y8`
{ J4::.r
String header=con.getHeaderFieldKey(i); y,x 2f%x
if(header!=null) MLHCBRi
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Sc>mw
Utility.log(header+" : "+con.getHeaderField(header)); 'sUOi7U
else IeYNTk&<
break; e&VC}%m
} l%"DeRp,/
} hHJvLs>^
k4LrUd
}vZf&ib-
public void splitterStop() -J+1V{
{ ~iH a^i?2*
bStop = true; :a;F3NJ
} it\$Pih]
O~V^]
q<q IT
} KMIe%2:b5
?m]vk|>
Dnw^H.
/* {. 9BG&
**FileAccess.java auK9wQ%\
*//文件访问(定位，写) \{ EVRRXn
package NetFox; giNXXjl
import java.io.*; azv173XZ
)v_Wn[Y.H
erEB4q+ #O
public class FileAccessI implements Serializable{ #U`AK9rP_g
1*hEbO
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _dd! nU\A|
RandomAccessFile oSavedFile; kiM:(=5
long nPos; LP#wE~K"b
YXWDbr:JX
U|Fqna
public FileAccessI() throws IOException v3Vve:}+
{ (1D1;J4g
this("",0); K^fs#7
} 5`p9Xo>)yW
yR>P
1(BLdP3&
public FileAccessI(String sName,long nPos) throws IOException g]vB\5uA:
{ K{DC{yLu
oSavedFile = new RandomAccessFile(sName,"rw"); N=1ue`i
this.nPos = nPos; ZEI)U, I.
oSavedFile.seek(nPos); ~@c<5 -`{
} (7G4v
E42)93~C
rt*x[5<
public synchronized int write(byte[] b,int nStart,int nLen) 88_ef7w
{ Bu=1-8@=qs
int n = -1; PEvY3F}_rh
try{ [oU\l+t
oSavedFile.write(b,nStart,nLen); f5 bq)Pm&
n = nLen; vmAnBY
} n5d8^c!2
catch(IOException e) `YqtI/-w
{ yk4@@kHW
e.printStackTrace (); c46-8z$
} Qa=Y?=Za
PSq?8.
/";tkad^
return n; p}!i_P
} ASbIc"S6
DW7E ]o
h s',f
} Zu|NF uFI
J;_4 3eS
L&kCI`Tb
/* D^@@ P
**SiteInfoBean.java D{B?2}X
*/ gEk;Tj
package NetFox; {4 Yxh8
Bz }nP9
G7&TMg7i
public class SiteInfoBean { DK?aFSf\
(o|bst][S
2@tnOs(*
private String sSiteURL; //Site's URL 9k;,WU(K<
private String sFilePath; //Saved File's Path aU(.LC
private String sFileName; //Saved File's Name oC|oh
private int nSplitter; //Count of Splited Downloading File s*Qyd{"z
%.=}v7&<z
!lfE7|\p
public SiteInfoBean() Vpg>K #w
{//nSplitter的缺省值为5 t~ {O)tt
//default value of nSplitter is 5 (5!'42
this("","","",5); 2JK '!Ry)
} Kc\8GkdB
nIg 88*6b,
+w]#26`d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,7@\e&/&
{ X,w X)9]J
sSiteURL= sURL; }BC%(ZH6
sFilePath = sPath; *w@1@6?j
sFileName = sName; Cqnuf5e>L
this.nSplitter = nSpiltter; aH."| *.
]?(kaNQ"D
i5TGK#3o
} \|S%zX
4:rwzRDY
flPS+
public String getSSiteURL() KR$Fd
{ 14'\@xJMM
return sSiteURL; x$-kw{N
} -/?)0E
iz-z?)%
5c::U=
public void setSSiteURL(String value) [voZ=+/
{ ~Fh+y+g?
sSiteURL = value; +ytP5K7
} q~> +x?30
Y!xPmL^]?
~b]enG5xS4
public String getSFilePath() >gp53\
{ v)O0i2
return sFilePath; 3/]1m9x
} E$ \l57
[Ep'm
rEWJ3*Hb
public void setSFilePath(String value) "yQBHYP
{ [mv? \HDa~
sFilePath = value; 9 3)fC
} ^Saf z8-3o
ZXs,TaU
nV8'QDQ:Al
public String getSFileName() d\>XfS
{ \ 86g y/
return sFileName; OD~Q|I(j
} t4UK~ {gh
HY5R
2!-Q!c`y
public void setSFileName(String value) `W1uU=c
{ KMi$0+
sFileName = value; GwF8ze+cH
} $[A^8[//
+&7V@
.9x*YS
public int getNSplitter() lU!_V%n
{ `_cv& "K9f
return nSplitter; -crMO57/
} a&JY x
3}\z&|
z` 6$p1U
public void setNSplitter(int nCount) PpFQoY7M
{ h.R46:
nSplitter = nCount; !T<,fR+8X
} X(/fE?%;
} VX8rM!3
1_{e*=/y
}i^M<A O
/* *~P| ? D'
**Utility.java -}<Ru)
*/ !k% PP
package NetFox; o}r_+\n
!IR cv a
_}[WX[Le{
public class Utility { +/celp
k5K5OpY
$H+X'1
public Utility() ^J>m4`
{ 3A^AEO
kkZ}&OXS;
L@O>;zp;
} 5nib<B%<V
;!f~
//线程睡眠 `r1j>F7Xb
public static void sleep(int nSecond) VB905%
{ gnZ#86sO
try{ J=Kv-@I>E
Thread.sleep(nSecond); Mw,]Pt6~i
} s/@uGC0>
catch(Exception e) wowf1j-
{ 8B-PsS|'
e.printStackTrace (); EE]xZz>o
} 1/mBp+D
} {wM<i
`\(co;:
//日志 EXeV@kg
public static void log(String sMsg) yg8=G vO
{ }JtcAuQt
System.err.println(sMsg); Z{vc6oj
} O-7)"
TI8\qIW
5yt=~
public static void log(int sMsg) i Ehc<
{ [ p,]/ ^ N
System.err.println(sMsg); 'V%w{ZiiV
} #tg\ bb
} OMk3\FV2Z
8Y8bFWuc
afHRy:<+%
/* bK}ZR*)
**TestMethod.java ;B |
*/ X,+a 6F
package NetFox; FWeUZI+
~m<K5K6 V
(t3gNin
public class TestMethod { DXD+,y\=
,? <;zq
8Ckd.HKpQ
public TestMethod() .0yBI=QI
{ ///xx/weblogic60b2_win.exe *\#<2 QAe
try{ "uuM#@h
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U*{0,Ue'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); W2-l_{
SiteFileFetch fileFetch = new SiteFileFetch(bean); A?04,l]y
fileFetch.start(); v(Kj6'
} 0= bXL!]
catch(Exception e){e.printStackTrace ();} Q'jGNWep
f9UDH8X
Efe(tH2q
} mEYfsO
9[\do@
TT9 \m=7
public static void main(String[] args) k;<@2C
{ g:~q&b[q6
new TestMethod(); bHm/ZZx
} RLex#j
} 13 L&f\b
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