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)); jxoEOEA
} #/ 4Wcz<
for(int i=0;i<nEndPos.length-1;i++) ^{Vm,nAQqs
{ es6e-y@e
nEndPos = nStartPos[i+1]; EP8LJzd"
} ~Ep&:c4:D
nEndPos[nEndPos.length-1] = nFileLength; [Dt\E4
} O:U@m@7
} h\dIp`H
YW'Y=*
c49#aNR
//启动子线程 /# eBDo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'Oc8[8
for(int i=0;i<nStartPos.length;i++) NMDNls&)k
{ Z/I!\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q\rqG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i3GvTg-X
nStartPos,nEndPos,i); =?2y <B
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6RF01z|~_
fileSplitterFetch.start(); Z5U~g?
} q+DH2&E'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J^XH^`'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); A1@-;/H3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YU"Am !
nEndPos = " + nFileLength); =#u2Rx%V
// fileSplitterFetch[nPos.length-1].start(); b'&pJ1]]}
}Q%>Fv
:.~a[\C@V<
//等待子线程结束 2iGRw4`_a
//int count = 0; dOhV`8l
//是否结束while循环 01dx}L@hz
boolean breakWhile = false; W@G[ gS\T
Y[H_?f=;%
Za} |Ee
while(!bStop) ^4[\-L8Lpq
{ ?yz%r`;r
write_nPos(); (kHR$8GFM
Utility.sleep(500); ^AM_A>HnG
breakWhile = true; 1t0FJ@)*
1D`RR/g&
{, |"Rpd
for(int i=0;i<nStartPos.length;i++) ~L1O\V i
{ w0IB8GdF
if(!fileSplitterFetch.bDownOver) {$t*Mb0
{ Yyo|W;a]
breakWhile = false; h<M7[p=
break; NWg\{a
} &SM$oy#?
} `SW " RLS3
if(breakWhile) CvW((<?
break; D7.P
~Qsj)9
jysV%q 3
//count++; HLk"a-+'
//if(count>4) ""+*Gn7^8
// siteStop(); Fs|;>Up0
} p^:Lj9Qax
CJOl|"UyJ
OW}A48X[+
System.err.println("文件下载结束！"); OgS8.wX
} *N r|G61
catch(Exception e){e.printStackTrace ();} QT$1D[>
} FNM"!z
=Q}mJs
w'0M>2
//获得文件长度 &-:yn&f7
public long getFileSize() nc~d*K\!
{ }Yl=lcvw
int nFileLength = -1; gk1S"H
try{ X-,y[ )
URL url = new URL(siteInfoBean.getSSiteURL()); eW)I}z+{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'lk74qU$
httpConnection.setRequestProperty("User-Agent","NetFox"); fti|3c
"V0:Lq
}?J5!X
int responseCode=httpConnection.getResponseCode(); ~k0)+D}
if(responseCode>=400) mJ>99:W+
{ Iq]6]
processErrorCode(responseCode); [Be53U{=
return -2; //-2 represent access is error 6a7iLQA
} !#I/be]
d`<^+p)oy
DB%AO:8
String sHeader; rOHW
V8$bPVps
1GE%5
for(int i=1;;i++) &[Zap6]
{ T\!SA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); %OW9cqL>l
//Utility.log(in.readLine()); YIQ]]q8R!L
sHeader=httpConnection.getHeaderFieldKey(i); wV&f|JO0+
if(sHeader!=null) rY?F6'}
{ ZV]e-
if(sHeader.equals("Content-Length")) tW:/R@@
{ 'xZPIj+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6a?$=y
break; *\:_o5o%[T
} .S'fM]_#
} Ru^ ONw"
else FgQ_a/*
break; FNm6/_u3
} N3yB1_
} Qy^z*s
catch(IOException e){e.printStackTrace ();} kad;Wa#h
catch(Exception e){e.printStackTrace ();} d6@jEa-
W+f&%En
J&"?m.~@
Utility.log(nFileLength); G(OT"+O,
ow+Dd[i
X'#$e{
return nFileLength; r d6F"W
} f;Bfh3
]fADaw-R
4-+ozC{
//保存下载信息（文件指针位置） mbX)'. +L
private void write_nPos() RCh$j&Tn
{ Wz-3?EQ
try{ BgkB x
output = new DataOutputStream(new FileOutputStream(tmpFile)); |)?aH2IL
output.writeInt(nStartPos.length); :q>oD-b$}
for(int i=0;i<nStartPos.length;i++) -Y8ks7
{ Z6R: rq
// output.writeLong(nPos); Z<N&UFw7QJ
output.writeLong(fileSplitterFetch.nStartPos); 6L8tz8
output.writeLong(fileSplitterFetch.nEndPos); up&NCX
} <E[HlL
output.close(); (~G5t(+
} 5X`w&(]m
catch(IOException e){e.printStackTrace ();} :m*!?QGdL
catch(Exception e){e.printStackTrace ();} D/S>w(=
} &Mhv XHI
{b|3]_-/
8<yV
//读取保存的下载信息（文件指针位置） \ W 'i0+
private void read_nPos() <+T\F;
{ *(d6Z#
try{ L}}=yh6r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "%oH@ =
int nCount = input.readInt(); ~U"by_
nStartPos = new long[nCount]; "Ju/[#VCJ
nEndPos = new long[nCount]; X,WQ'|rC
for(int i=0;i<nStartPos.length;i++) .DDg%z
{ `Di ^6UK(
nStartPos = input.readLong(); mUrS&&fu8
nEndPos = input.readLong(); r~$}G-g
} E!zd(
input.close(); 4_Qa=T8
} r,2Xu
catch(IOException e){e.printStackTrace ();} %[]"QbF?
catch(Exception e){e.printStackTrace ();} gp~yt0AU
} @-wNrW$
});cX$
ny12U;'s,
private void processErrorCode(int nErrorCode) 35Ai;mU'
{ .'t (-eT,
System.err.println("Error Code : " + nErrorCode); :3KO6/+
} @-'/__cgt
(3 IZ
>Z#uFt0<Pm
//停止文件下载 pN\)(:"8v
public void siteStop() A Gv!c($
{ >I$B=
bStop = true; H$z>OS_6U
for(int i=0;i<nStartPos.length;i++) z.eJEK
fileSplitterFetch.splitterStop(); $|4cJ#;^L
!]$V9F{K
R%>jJ[4\[
} 9#v-2QY
} cC^W2\
//负责部分文件的抓取 iuiAK
**FileSplitterFetch.java 'e}uvbK
*/ {eEBrJJeB
package NetFox; _Zh2eXWdjM
R=!kbBK>\
KMUK`tbaI
import java.io.*; *:a'GC%/
import java.net.*; -glugVq
1TKEm9j]u
6ayy[5tW
public class FileSplitterFetch extends Thread { ?q\FLb%"7
x>}B#
):e+dt
String sURL; //File URL %1Yz'AiW[
long nStartPos; //File Snippet Start Position H5~1g6b@
long nEndPos; //File Snippet End Position he"L*p*H
int nThreadID; //Thread's ID Hal7 MP
boolean bDownOver = false; //Downing is over N? M
boolean bStop = false; //Stop identical m;dm|4L^
FileAccessI fileAccessI = null; //File Access interface Vzpt(_><
J0=7'@(p
?-pi,O~(p
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y<TOqn
{ N1%p"(
this.sURL = sURL; .Y;b)]@f
this.nStartPos = nStart; 1Q]Rd
this.nEndPos = nEnd; UEzsDJu
nThreadID = id; 5L F/5`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ',GV6kt_k
} @<2d8ed
nTPB,QE<
z5'ZN+
public void run() `ruNA>M
{ '_V #;DI
while(nStartPos < nEndPos && !bStop) k0L] R5W
{ ^=^$tF
PY?8[A+
b(l0js
try{ TjxA#D)
URL url = new URL(sURL); {Bh("wg$Lk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,of]J|
httpConnection.setRequestProperty("User-Agent","NetFox"); Y&K <{\vE
String sProperty = "bytes="+nStartPos+"-"; +c--&tBo
httpConnection.setRequestProperty("RANGE",sProperty); Pe}PH I
Utility.log(sProperty); ~O{W;Cyh
e # 5BPI
GX }q9
InputStream input = httpConnection.getInputStream(); `N}d}O8
//logResponseHead(httpConnection); dy2rkV.z
FbAW_Am(
eCWPhB6l
byte[] b = new byte[1024]; D^+?|Y@N
int nRead; &+01+-1hW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) CQgcC-)ns]
{ !77NG4B
nStartPos += fileAccessI.write(b,0,nRead); io.]'">
//if(nThreadID == 1) )#C mQXgG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [}-3PpF
} CE ~@}`
QB&BTT=!
9pLg+6O
Utility.log("Thread " + nThreadID + " is over!"); _'!kuE,*1
bDownOver = true; E"qFXA>
//nPos = fileAccessI.write (b,0,nRead); | kXm}K
} U%>'"
catch(Exception e){e.printStackTrace ();} HbM0TXo
} booRrTS
} .WX,Nd3@
Q`ME@vz
W2]TRO
//打印回应的头信息 `)Ky0&?
public void logResponseHead(HttpURLConnection con) eg<pa'Hw
{ uwmQ?LS]V
for(int i=1;;i++) %w ) +V
{ `VT>M@i/
String header=con.getHeaderFieldKey(i); qf#)lyr<D6
if(header!=null) iPj~I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); C&<~f#lB
Utility.log(header+" : "+con.getHeaderField(header)); ZVih=Y-w
else +v7) 1y
break; Z[?mc|*x
} Z>P*@S,6G
} F #`=oM$5
6RoAl$}'
ny*i+4Mb
public void splitterStop() rD &D)w
{ 8b(!k FxD
bStop = true; O;uG?.\
} )[Z!*am
L]%l51U
0~Gle:
} Fhf<T`
viX +|A4gJ
aYn^)6^
/* ?-)I+EAnE
**FileAccess.java 7[pBUDA
*//文件访问(定位，写) 9=`Wp6Gmn
package NetFox; M@et6aud;K
import java.io.*; oUZoj2G1
5GzFoy)j>
soRv1)el
public class FileAccessI implements Serializable{ }<a^</s
c9"r6j2m5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IxZb$h[
RandomAccessFile oSavedFile; /]^#b
long nPos; Ifc]K?
W/$Zvl
KngTc(^_D
public FileAccessI() throws IOException RE2&mYt
{ ^TY;Zp
this("",0); E H:T
} w8S!%abl1
D\dWt1n
fxaJZz$o
public FileAccessI(String sName,long nPos) throws IOException !E8X~DJ
{ G2bDf-1ew
oSavedFile = new RandomAccessFile(sName,"rw"); H,3\0BKk
this.nPos = nPos; nn/?fIZN4
oSavedFile.seek(nPos); U1_@F$mq<
} \MC-4Yz
JxE53ev
eV:9y
public synchronized int write(byte[] b,int nStart,int nLen) &s Pq<lo
{ jp8@vdRg
int n = -1; _.IxRk)T
try{ ^bg2[FV
oSavedFile.write(b,nStart,nLen); ,YTIC8qKr
n = nLen; 3$.deYa$R
} wN1niR'
catch(IOException e) <h%O?mkC
{ gVQjL+_W
e.printStackTrace (); ;c~cet4
} {~!q`Dr3?q
z%MW!x
wW>zgTG
return n; -p3Re9
} w(kf
+a-6Q ~
w0w G-R ?
} I2nF-JzD2a
|f~@8|MQP+
yFDv6yJ.
/* =mA: ctu~v
**SiteInfoBean.java l @^3Exwt
*/ U2uF&6v
package NetFox; pw7[y^[Qg
H*#s }9=kZ
WVVJ
public class SiteInfoBean { G}&Sle]
iw*Nq,(
3nZo{p:E
private String sSiteURL; //Site's URL /pF`8$
private String sFilePath; //Saved File's Path oc8:r
private String sFileName; //Saved File's Name ;&1V0U,fx
private int nSplitter; //Count of Splited Downloading File 5:'hj$~|\1
7S?4XyU/o
iD<(b`S
public SiteInfoBean() W5SJ^,d)J
{//nSplitter的缺省值为5 `jwa<N4e@
//default value of nSplitter is 5 f=)2f=
this("","","",5); -_`>j~
} L!=QR8?@E
^^5&QSB:'
Pp )3(T:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qUly\b 47
{ FJasS8
sSiteURL= sURL; P2bZ65>3y
sFilePath = sPath; 27;ci:5
sFileName = sName; foQ#a
this.nSplitter = nSpiltter; w8n|B?Sr
cReB~wk
{mAU3x
} `ho1nY$)CE
~8lwe*lNV
s8}@=]aA
public String getSSiteURL() H,b5C_D29
{ O BN2 ) j
return sSiteURL; iezO9`
} !Y-98<|b M
k1QpKn*
)oyIe)
public void setSSiteURL(String value) g1jTy7g?
{ Rz.?i+
sSiteURL = value; o LvZ
} '_V2!?+RU+
V3"=w&2]K
7AObC4 g
public String getSFilePath() uvrB5=u
{ #FNcF>3>
return sFilePath; iRrl^\qn
} VY3&
~J P=T
$C `;fA
public void setSFilePath(String value) +(h\fm7*-
{ zRyuq1Zyc,
sFilePath = value; %HL*c=
} 7k rUKYVo
Ry'= ke
)BwjZMJ.N
public String getSFileName() ;1a~pF S
{ ypy68_xyW
return sFileName; Rp5#clsy
} ;dJ1
T3^GCX|!@
=F@Wgn,
public void setSFileName(String value) 9o+)?1\
{ }nL7T'$>
sFileName = value; f`;j:O
} {QwHc5Bf
}yz (xH
PBp^|t]E>
public int getNSplitter() 7:2WgLo
{ gy_>`16K
return nSplitter; zR{W?_cV
} h]TQn)X]
3h *!V6%q
oIduxbAp
public void setNSplitter(int nCount) xjVS
{ D`$hPYK|_
nSplitter = nCount; @9lUSk^9
} v^1pN>#%g
} SF>c\eTtx
o<|P9#(U"
/|D*w^>
/* [_Qa9e
**Utility.java `a2n:F
*/ e8GEoD
package NetFox; u)~C;f)
\Z+z?K O
l\@)y4 +
public class Utility { iLkZ"X.'|1
%|^fi8!:|
K5xX)oV
public Utility() ~1>.A(,=z
{ PEc=\?
ce7CcHQ?B
Yo|,]X>/
} <c2'0I >
&FF"nE*
//线程睡眠 [rSR:V?"a
public static void sleep(int nSecond) [D<1CF
{ a+%6B_|\
try{ :(M(>4t
Thread.sleep(nSecond); "CI=`=
} !0vG|C;'
catch(Exception e) uA#P'?
{ ;n&t>pBM
e.printStackTrace (); OHhsP}/
} +Zaj,oEE
} `1bv@yzq
!Rhlf.x
//日志 ,}K7Dg^1
public static void log(String sMsg) BZ?.D_bu
{ #?/<
System.err.println(sMsg); ' <@3i[M
} LdL/399<
Wwr;-Qa}g
w tiny,6
public static void log(int sMsg) i:OK8Q{VI
{ n}!PO[m~
System.err.println(sMsg); !& z(:d
} .MP !`
} O vk_\On
GJoS#s
x7eQ2h6O
/* c'S,hCe*
**TestMethod.java M!REygyx
*/ F!]lU`z)=
package NetFox; 7~5ym15*
4UW_Do
#0y)U;dA+w
public class TestMethod { \cUC9/ b
VB,?Mo}R
4}eepJOn
public TestMethod() qa0 yg8,<
{ ///xx/weblogic60b2_win.exe id2j7|$,
try{ F7O(Cy"1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i5CK*"$Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JNJ=e,O,
SiteFileFetch fileFetch = new SiteFileFetch(bean); VCD:3U 8
fileFetch.start(); 8j=}u/T@F
} x6e}( &p*
catch(Exception e){e.printStackTrace ();} tX> G,hw
9*{[buZX
)~HUo9K9
} k{Me[B
6y9t(m
!g(KK|`,m
public static void main(String[] args) QT>`^/]d
{ U8LtG/
new TestMethod(); G"Sd@%W(
} iC98_o_9
} f;xkT
点击下载更多相关资料