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^'
} +AL(K:
for(int i=0;i<nEndPos.length-1;i++) +U,>D+
{ 2f.4P]s`T
nEndPos = nStartPos[i+1]; o'p[G]NQ1o
} &!O~ f
nEndPos[nEndPos.length-1] = nFileLength; !7aJfs2
} Bhw|!Y&%
} ;>B06v
3dC;B@
k^r-~q+NV#
//启动子线程 #BX^"J{~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $nW^Gqwj]1
for(int i=0;i<nStartPos.length;i++) pN7 v7rs
{ 1U~yu&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~QE-$;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;n=A245W\
nStartPos,nEndPos,i); kK$*,]iCp
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y,=TB[d#
fileSplitterFetch.start(); *p7_rY
} \x+"1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -WK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g'1ASMuR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \9s x_T
nEndPos = " + nFileLength); -87]$ ax
// fileSplitterFetch[nPos.length-1].start(); @2)ImgK[
^Ts8nOGMh
J9yB'yE8
//等待子线程结束 ?u_O(eg
//int count = 0; #Vh$u%q3
//是否结束while循环 ~F=,)GE
boolean breakWhile = false; Z|qUVD5Ic
cp<jwcc!
]*JH~.p
while(!bStop) 7.tEi}O&_g
{ gVI2{\a
write_nPos(); d]w%zo,yr
Utility.sleep(500); :pPn)j$
breakWhile = true; ~TfQuIvQB
X3,+aL`
Ld3!2g2y7&
for(int i=0;i<nStartPos.length;i++) "4e{Cq
{ OFcqouGE
if(!fileSplitterFetch.bDownOver) rLOdQN
{ 5RhP^:i@C
breakWhile = false; D!CuE7}
break; )90K^$93"
} R SqO$~
} 'or8CGr^p
if(breakWhile) !`EhVV8u-_
break; C#4/~+
caC(KK#<
O\KSPy7YQ
//count++; ~7Jj\@68
//if(count>4) #Ez+1
// siteStop(); cWNWgdk,`V
} Tx\g5rk
,7nA:0P
K5SP8<.
System.err.println("文件下载结束！"); ?^H1X-;
} Jdp@3mP
catch(Exception e){e.printStackTrace ();} o:"^@3
} k=):>}
?sm@lDZ\
S2*ER
//获得文件长度 auT'ATW7i
public long getFileSize() |=W=H6h*
{ hCKx%&[^7
int nFileLength = -1; VPqMbr"L[
try{ zS+_6s
URL url = new URL(siteInfoBean.getSSiteURL()); R x.]m0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {f<\`
httpConnection.setRequestProperty("User-Agent","NetFox"); K JX@?1"
e<[0H 8
OGqsQ
int responseCode=httpConnection.getResponseCode(); ,%%}d9
if(responseCode>=400) fK{[=xMr@
{ JDy;Jb
processErrorCode(responseCode); =j{r95)|u
return -2; //-2 represent access is error b&1-tYV
} <m3or
/)E'%/"A
duk:: |{F
String sHeader; KGoHn6jM
l`A4)8Y@
Lb} cjI:
for(int i=1;;i++) 4]/i0\Vbam
{ p3YF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =ap6IVR
//Utility.log(in.readLine()); =YRN"
sHeader=httpConnection.getHeaderFieldKey(i); ^#A[cY2eM
if(sHeader!=null) SJdi*>
{ r9d dVD
if(sHeader.equals("Content-Length")) t@O4!mFH
{ 9M$N>[og
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f8'$Mn,
break; O#5ll2?
} , JUP
} 1KtPq,
else (ATCP#lF
break; 8K/o/
} q4rDAQyPO
} :&oUI&(o
catch(IOException e){e.printStackTrace ();} Lv{xwHnE
catch(Exception e){e.printStackTrace ();} )"o+wSI1
^3:DeZf!u
|rbl sL2?Z
Utility.log(nFileLength); ax)j$
:9Vd=M6,
+e6c4Tw/
return nFileLength; 2!4.L&Ki
} '#b7Z?83C
_7M!b9oA
ToB^/ n[
//保存下载信息（文件指针位置） 5@{+V!o,
private void write_nPos() Mn=5yU
{ +.b@rU6H
try{ )5Bkm{v3
output = new DataOutputStream(new FileOutputStream(tmpFile)); a}w%k
output.writeInt(nStartPos.length); khW9n*
for(int i=0;i<nStartPos.length;i++) X0.-q%5
{ P6E=*^^m(
// output.writeLong(nPos); +L$,jZqS
output.writeLong(fileSplitterFetch.nStartPos); Kx;DmwX-
output.writeLong(fileSplitterFetch.nEndPos); M5Twulz/w
} b:iZ.I
output.close(); gAY%VFBP0
} @-ma_0cZQ
catch(IOException e){e.printStackTrace ();} p~sfd
catch(Exception e){e.printStackTrace ();} weOzs]uc
} D-8>?`n\
<9s=K\-
f2#9E+IQ
//读取保存的下载信息（文件指针位置） R "&(Ae?LR
private void read_nPos() /Lc= K<
{ 2z\4?HJy
try{ 7Pc0|Z/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w$5N6
int nCount = input.readInt(); {xC CUU
nStartPos = new long[nCount]; 'ZHu=UT7_
nEndPos = new long[nCount]; WLAJqmC]
for(int i=0;i<nStartPos.length;i++) >Ufjmm${
{ ikGH:{
nStartPos = input.readLong(); yMNLsR~rh
nEndPos = input.readLong(); ,Dz2cR6
} x,Cc$C~YP
input.close(); l}DCK
} IKK<D'6
catch(IOException e){e.printStackTrace ();} K+` Vn
catch(Exception e){e.printStackTrace ();} :);]E-ch
} NS l$5E
5g-apod
vl@t4\@3
private void processErrorCode(int nErrorCode) 1]@}+H
{ 9@yP;{Q
System.err.println("Error Code : " + nErrorCode); p0.?R
} n(Up?_
$l&&y?()
~?}/L'q!b
//停止文件下载 (/_Q r2KfC
public void siteStop() P#H#@:/3
{ gKZ{O
bStop = true; |<.b:e\4
for(int i=0;i<nStartPos.length;i++) 6bg+U`&g
fileSplitterFetch.splitterStop(); dv0TJ 0%
0;)6ZU
|zu>G9m
} K)qbd~<\
} sQ^>.yG
//负责部分文件的抓取 Y\T*8\h_[
**FileSplitterFetch.java rI}E2J
*/ ~zz|U!TG
package NetFox; ru`;cXa,
T^a {#B
13Z6dhZu
import java.io.*; ;f-|rC_"
import java.net.*; W4CI=94
$/C<^}A
71tMX[x
public class FileSplitterFetch extends Thread { JLAg-j2
#{0DpSzE5
81_3{OrE<
String sURL; //File URL D,eJR(5I
long nStartPos; //File Snippet Start Position Snt=Hil`
long nEndPos; //File Snippet End Position H/V%DO
int nThreadID; //Thread's ID uz4mHyS6
boolean bDownOver = false; //Downing is over 4C/8hsn
boolean bStop = false; //Stop identical q rbF@{
FileAccessI fileAccessI = null; //File Access interface hkgPC-
+&\TdvNI4
l@*/1O)v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J'O`3!Oy/
{ [6S"iNiyKT
this.sURL = sURL; =] 5;=>(
this.nStartPos = nStart; <nsl`C~6g0
this.nEndPos = nEnd; l1cBY{3QD
nThreadID = id; LbR/it'}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eq/5$b(
} [Pp#l*
!E_uQ?/w]Z
z K8#gif@
public void run() ~DZ;l/&Mz7
{ p2~Q
while(nStartPos < nEndPos && !bStop) &SN$D5U'
{ (P#2Am$
o33{tUp'
+lha^){
try{ l3MbCBX2
URL url = new URL(sURL); qd|*vE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CES FkAj~
httpConnection.setRequestProperty("User-Agent","NetFox"); !T,7
String sProperty = "bytes="+nStartPos+"-"; TjI NxP-O
httpConnection.setRequestProperty("RANGE",sProperty); a`pY&xq::
Utility.log(sProperty); <vt^=QA'
)dL?B9d:
0K3FH&.%
InputStream input = httpConnection.getInputStream(); ($(1KE
//logResponseHead(httpConnection); *vAOUqX`x
g&0GO:F`
4_.k Q"'DH
byte[] b = new byte[1024]; J|FyY)_
int nRead; &<Gq-IN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1]>KuXd r
{ IPxfjBC+J
nStartPos += fileAccessI.write(b,0,nRead); l!AZ$IV
//if(nThreadID == 1) u F*cS&'Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ex!^&7Q(
} 4}LF>_+=
@B9|{[P
x>8f#B\Mr
Utility.log("Thread " + nThreadID + " is over!"); MZjiJZaO:L
bDownOver = true; Mqh~5NM
//nPos = fileAccessI.write (b,0,nRead); F[=m|MZb
} ''v1Pv-
catch(Exception e){e.printStackTrace ();} d7^XP
} 8e\v5K9
} _&%!4n#>
e4)gF*
sId5pY!
//打印回应的头信息 aq5<Ks`r
public void logResponseHead(HttpURLConnection con) 93WYZNpX
{ ~v54$#CB
for(int i=1;;i++) iz^wBQ
{ R-Fi`#PG2
String header=con.getHeaderFieldKey(i); *>'R R<
if(header!=null) lwg.'<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;W+-x]O
Utility.log(header+" : "+con.getHeaderField(header)); Z],"<[E
else rbtV,Y
break; 4P~<_]yf
} \~)573'
} GO)rpk9
kN$70N7I;
H0(zE*c~
public void splitterStop() Fp]8f&l8
{ -.*\J|S@g
bStop = true; M<p)@p
} :9h8q"T
"G,*Z0V5
%@&)t?/=
} &V:dcJ^Q
]czy8n$+
)[K3p{4
/* ibuI/VDF
**FileAccess.java aXJe"IT.u
*//文件访问(定位，写) Y@4vQm+
package NetFox; XP`kf]9
import java.io.*; qJ/C*Wqic
8Cqs@<r4Od
|@g1|OWd|
public class FileAccessI implements Serializable{ 5->PDp
OX`n`+^D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jF;4 8g@^
RandomAccessFile oSavedFile; i@J,u
long nPos; \O:xw-eG
\S<5b&G
O+8`.
public FileAccessI() throws IOException UJH{vjIv
{ @ubz?5
this("",0); \fz j fZ1n
} 5VTbW
[]]3"n
@ tIB'|O
public FileAccessI(String sName,long nPos) throws IOException `@eH4}L*
{ 'AAY!{>
oSavedFile = new RandomAccessFile(sName,"rw"); f5a](&
this.nPos = nPos; Xp~]kRm9
oSavedFile.seek(nPos); ;gMh]$|"
} "P{&UwMmh
u .2sB6}
7asq]Y}<
public synchronized int write(byte[] b,int nStart,int nLen) XJzXxhk2
{ ".)_kt[
int n = -1; O$H150,Q
try{ H+;wnI>@
oSavedFile.write(b,nStart,nLen); _5T7A><q<
n = nLen; ^8m+*t
} @,MdvR+a
catch(IOException e) /(V=Um^0
{ >&&xJ5
e.printStackTrace (); UYQ$c }Z5
} g,:Nzb
6\3k0z
[KH?5C
return n; DOerSh_0W
} 3I5WDuq
QRlzGRueR&
Ng"vBycy
} i-?zwVmn
@;6}xO2
+I<Sq_-
/* faq K D:
**SiteInfoBean.java %jxuH+L
*/ >D/~|`=p
package NetFox; #& wgsGV8C
?Qig$
)!d1<p3
public class SiteInfoBean { gn"&/M9E
OQ7c|O
AuTplO0_rE
private String sSiteURL; //Site's URL <dL04F
private String sFilePath; //Saved File's Path h,>L(=c$O
private String sFileName; //Saved File's Name ^I{]Um:
private int nSplitter; //Count of Splited Downloading File kMl<
nEm7&Gb
:*@|"4
public SiteInfoBean() *$(CiyF!
{//nSplitter的缺省值为5 @(c<av?
//default value of nSplitter is 5 @S7=6RKa[
this("","","",5); H040-Q;S'
} : xZC7"
aELT"b,x
h!K2F~i{P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ['emP1g~
{ %h"< IA S.
sSiteURL= sURL; A{2$hKqHi
sFilePath = sPath; txo?k/w
sFileName = sName; vB5iG|b}
this.nSplitter = nSpiltter; +&,\ J9'B
PAwg&._K
[T]qm7 ?
} O{#Cddt:r
-C ON
G=cH61
public String getSSiteURL() 2w|u)ow)
{ 9'q/&uH
return sSiteURL; <88}+j
} hZWK5KwT
T(UYlLe
mzxvfXSF
public void setSSiteURL(String value) iT5SuIv
{ \~t~R q
sSiteURL = value; '1'1T5x~
} 9!HMQ
.eNwC.8i
s66XdM
public String getSFilePath() ~cBc&u:"
{ Z034wn\N
return sFilePath; R%_H\-wo
} &NjZD4m`=
b*F~%K^i$
~|{)h^]@
public void setSFilePath(String value) Vfm #UvA
{ = )l:^+q
sFilePath = value; "!Oh#Vf
} DUKmwKM"k
yr9A0F0
|C6(0fgWd
public String getSFileName() pZ~>l=-
{ V1nZ M
return sFileName; $t# ,'M
} XjZao<?u
BMWeD
B"8JFf}"q
public void setSFileName(String value) X,EYa>RSy_
{ a/<pf\O
sFileName = value; csX*XiDWm
} gQd=0"MV
d<GG(
p5;,/ |Ft
public int getNSplitter() w+9C/U;|s
{ J=SB/8tQ)T
return nSplitter; a-A+.7
} cw]>a&d
K'5sn|)
mz$Wo *FB
public void setNSplitter(int nCount) =R;1vUio
{ [{p?BTs
nSplitter = nCount; -)a_ub
} 8pL>wL &C
} ]7S7CVDk4
sJI-
'"]>`=R
/* 0?Tk*X
**Utility.java o%^k T&
*/ }Q r0T
package NetFox; h[je_^5
B,vHn2W
JNM@Q
public class Utility { TQ\wHJ
fFZ`rPb
MZMS?}.2
public Utility() xK),:+G(
{ S,Wl)\
b8{h[YJL2
b!5tFX;J
} OwiWnS<
),p]n
//线程睡眠 f-v ND'@
public static void sleep(int nSecond) *fvI.cKiGP
{ 3w^J"O/T
try{ ^,Y~M_=
Thread.sleep(nSecond); ^W[B[Y<k
} ghobu}wuF
catch(Exception e) vi!r8k
{ w] 5U
e.printStackTrace (); fv j5[Q
} dy6F+V\DG
} U8QR*"GmT
8A8xY446)
//日志 j^$3vj5E[
public static void log(String sMsg) x#F1@r8R
{ RSPRfYU/
System.err.println(sMsg); xU13fl
} ttbQergS
M~z(a3@[V
}lC64;yo
public static void log(int sMsg) f}lT|.)?VD
{ DA4edFAuE
System.err.println(sMsg); jWv3O&+?X
} {GX &)c4
} ndKvJH4
@u"kX2>Eq
C?/r}ly<\
/* SD|4ybK>d
**TestMethod.java c5iormb"#
*/ m.HX2(&\3
package NetFox; -@ UN]K
k;K> ,$F
z%}CBTm
public class TestMethod { ]cLEuE^&
:rTKqX&"j
QSn;a 4f
public TestMethod() 7SA-OFM
{ ///xx/weblogic60b2_win.exe 7>t$<J
try{ s;-78ejj7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n $O.>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N'eQ>2>O@
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9N*S-Po=
fileFetch.start(); C>JekPeM
} hyk|+z`B
catch(Exception e){e.printStackTrace ();} yd0=h7s
>ggk>s|
z,}c?BP
} EDq$vB
tyn?o
qL%.5OCn(
public static void main(String[] args) 0uVk$\:i
{ r3[t<xlFf
new TestMethod(); r}_Lb.1]
} 2<y}91N:
} n!kk~65|
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