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)); *><j(uz!
} %tkqWK:
for(int i=0;i<nEndPos.length-1;i++) ;,Vdj[W$>
{ >;G_o="X
nEndPos = nStartPos[i+1]; `ci P
} iU.` TqR7
nEndPos[nEndPos.length-1] = nFileLength; vH6(p(l
} TH4f"h+B3"
} GAH<
VKXi*F9
EO'+r[Y
//启动子线程 nS$4[!0
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9i#,V@
for(int i=0;i<nStartPos.length;i++) xz@*V>QT
{ si%V63^lN
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Nc6y]eGz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uR")@Tc
nStartPos,nEndPos,i); ;N!n06S3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MeV4s%*O+
fileSplitterFetch.start(); g0~m[[
} 0*^f EoV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s!09cS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5Q}HLjG8Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ( K-7z
nEndPos = " + nFileLength); *s1o?'e
// fileSplitterFetch[nPos.length-1].start(); lh0G/8+C
zxv y&
K~&3etQF
//等待子线程结束 ,iiI5FR
//int count = 0; Q\~#cLJ/
//是否结束while循环 $ ga,$G
boolean breakWhile = false; qsN}KgTjg
@uxg;dyI~
Oa5-^&I
while(!bStop) Odt<WG
{ Q Na*Y@i
write_nPos(); 'wLW`GX.
Utility.sleep(500); T2T?)_f /
breakWhile = true; odeO(zuU
dZJU>o'BG
&6Wim<*
for(int i=0;i<nStartPos.length;i++) $iy(+}
{ Y^?PHz'Go
if(!fileSplitterFetch.bDownOver) /{ 8.Jcx$
{ tN)Vpb\J
breakWhile = false; dI,H:g
break; ,l)AYu!q4F
} H,fVF837
} {6*UtG
if(breakWhile) j;rxr1+w
break; :)Nk
U%2{PbL
/P{'nI
//count++; #4sSt-s&
//if(count>4) M w+4atO4[
// siteStop(); aOW~! f/M
} X`}4=>
Yceex}X*5
QRY7ck:N
System.err.println("文件下载结束！"); 5sMyH[5zY
} ?rwHkPJ{*
catch(Exception e){e.printStackTrace ();} YP}r15P
} Ef6LBNWY.
6FI`0j=~
!:dhK
//获得文件长度 y=WCR*N
public long getFileSize() nqujT8
{ W QyMM@#
int nFileLength = -1; V_Y2@4
try{ 771r(X?Fa
URL url = new URL(siteInfoBean.getSSiteURL()); ^d/,9L\U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `l}r&z(8
httpConnection.setRequestProperty("User-Agent","NetFox"); !%yd'"6Dl
jowR!rqf
/\uW[mt
int responseCode=httpConnection.getResponseCode(); =^3B&qQNq
if(responseCode>=400) \M-$|04Qt
{ cX-)]D
processErrorCode(responseCode); `lq[6[n
return -2; //-2 represent access is error d[Rs
} so\8.(7n
9RN! <`H
Xc@%_6
String sHeader; Z;_WU
=B(zW.Gf
l\yFx
for(int i=1;;i++) LV&tu7c
{ 7ST[XLwt%}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }cll? 2
//Utility.log(in.readLine()); dOFxzk,g&R
sHeader=httpConnection.getHeaderFieldKey(i); EV@xUq!x.
if(sHeader!=null) }XiS:
{ *fq=["O
if(sHeader.equals("Content-Length")) 1e;^MzB"
{ t`DoTb4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); pbivddi2
break; @>J4K#"
} zb}:wUR
} \)ac,i@fy
else HzM^Zn57%
break; aT#R#7<Eg
} V&DS+'P
} [KR`%fD0
catch(IOException e){e.printStackTrace ();} !9i,V{$c`"
catch(Exception e){e.printStackTrace ();} X+{4,?04+
(i7]N[
}`yIO"{8n
Utility.log(nFileLength); 7[55
"qb3\0O
{vAq08
return nFileLength; -lyT8qZ:(
} ocy fU=}X
:?{ **&=
`ejE)VL=8h
//保存下载信息（文件指针位置） jd=k[Yqr
private void write_nPos() 7vV3"uns
{ j3~:\H
try{ lC.Yu$O5
output = new DataOutputStream(new FileOutputStream(tmpFile)); bzmT.!
output.writeInt(nStartPos.length); 5-bd1!o
for(int i=0;i<nStartPos.length;i++) ekfD+X
{ {y'c*NS
// output.writeLong(nPos); (hVhzw"~
output.writeLong(fileSplitterFetch.nStartPos); lx~!FLn
output.writeLong(fileSplitterFetch.nEndPos); `w]=xe
} B[Uvj~g
output.close(); \Btv76*,
} ?K{CjwE.M
catch(IOException e){e.printStackTrace ();} [X=-x=S,
catch(Exception e){e.printStackTrace ();} H(!)]dO
} _5.^A&Y*
<r,l
~jmHzFkQ
//读取保存的下载信息（文件指针位置） X<_(gg
private void read_nPos() xe2Ap[Y'M
{ ju(&v*KA
try{ |~CN]N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); VLc=!W}
int nCount = input.readInt(); t&wtw
nStartPos = new long[nCount]; ;p/RS#
nEndPos = new long[nCount]; rFSLTbTf
for(int i=0;i<nStartPos.length;i++) t*82^KDU
{ |SZRO,7x
nStartPos = input.readLong(); @X"p"3V
nEndPos = input.readLong(); G#8HY VF
} fpJM)HU
input.close(); [x ?38
} 3zo]*6p0
catch(IOException e){e.printStackTrace ();} l)m\i_r:
catch(Exception e){e.printStackTrace ();} DmAMr=p
} ~X;r}l=k<
SPA_a\6_
xy`aR< L
private void processErrorCode(int nErrorCode) d|Wpub
{ \XwXs5"G
System.err.println("Error Code : " + nErrorCode); X~abn7_
} -[OGZP`8
ehj&A+Ip
,c_[`q\
//停止文件下载 o2?[*pa
public void siteStop() EOhUr=5~
{ `.nkC_d
bStop = true; p"ht|x
for(int i=0;i<nStartPos.length;i++) 4A0R07"
fileSplitterFetch.splitterStop(); ^.jIus5
k{Yj!C> #
Bn*D<<{T
} S*rgYe!E
} dUeM+(s1
//负责部分文件的抓取 q.i@Lvu#
**FileSplitterFetch.java " M8j?
*/ ->&AJI0
package NetFox; +#O?a`f
`Q6@,-(3
_m0HgLS~
import java.io.*; 6d"dJV.\
import java.net.*; 6grJoim|
PH97O`"
2H fP$.
public class FileSplitterFetch extends Thread { ("o<D{A
Lhu2;F\/
1eI>Yy>}
String sURL; //File URL i{PRjkR
long nStartPos; //File Snippet Start Position Hk8:7"4Q
long nEndPos; //File Snippet End Position .z7XYmv
int nThreadID; //Thread's ID 7qA);N
boolean bDownOver = false; //Downing is over YnuC<y &p
boolean bStop = false; //Stop identical s@ m A\
FileAccessI fileAccessI = null; //File Access interface ' ^gF
2fTkHBhn&
z~+_sTu
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hf0G-r_ow
{ BIDmZU9tL
this.sURL = sURL; VkhZt7]K}B
this.nStartPos = nStart; "cRc~4%K
this.nEndPos = nEnd; ,XCC#F(d1
nThreadID = id; 4JFi|oK0H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cEi{+rfZd|
} }qT @.
JT&CJ&#[h
rX%#Q\0h
public void run() :+ @-F>Q
{ oP5G*AFUq
while(nStartPos < nEndPos && !bStop) Tz+2g&+
{ 8,=Ti7_
e"hm|'
k!t5>kPSQ
try{ Mkko1T=6
URL url = new URL(sURL); I:uxj%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [yL%+I
httpConnection.setRequestProperty("User-Agent","NetFox"); n99:2r_
String sProperty = "bytes="+nStartPos+"-"; ?tE}89c
httpConnection.setRequestProperty("RANGE",sProperty); IK(G%dDw
Utility.log(sProperty); Crh5^?
4O9HoX#-?
5|x&Z/hL
InputStream input = httpConnection.getInputStream(); U}MU>kzb
//logResponseHead(httpConnection); ?,]%V1(@V`
"w=p@/C
03J,NXs
byte[] b = new byte[1024]; _a8^AG
int nRead; WW0N"m'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %MU<S9k
{ yopEqO
nStartPos += fileAccessI.write(b,0,nRead); g$ZgR)q
//if(nThreadID == 1) N'Ywn}!js
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5dT-{c%w4
} JxiLjvIq
-WE pBt7*
)"|'=
Utility.log("Thread " + nThreadID + " is over!"); f,d @*E
bDownOver = true; P9:7_Vc
//nPos = fileAccessI.write (b,0,nRead); dwv xV$Nt
} wWY6DQQB
catch(Exception e){e.printStackTrace ();} D(Zux8l
} :RzcK>Gub=
} Ig"Krz
QB#f'X
>wej1#\3
//打印回应的头信息 <5@+:7Dv
public void logResponseHead(HttpURLConnection con) {F6hx9?
{ gEIjG
for(int i=1;;i++) Of7j~kdh83
{ DGO_fR5L
String header=con.getHeaderFieldKey(i); ~bL(mq
if(header!=null) z[0L?~$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0fxA*]h
Utility.log(header+" : "+con.getHeaderField(header)); LDBxw
else ,8;;#XR3
break; ;dRTr *
} .(VxeF(v_k
} @{@x2'-A
;EW]R9HCH
9Wb9g/L
public void splitterStop() +I/7eIG?|
{ 7F4$k4r<
bStop = true; (+4gq6b
} .r[DqC
"%D+_Yb'X
{O5;V/00}
} llhJ,wD
6?+bi\6
RxAWX?9Z
/* 8yOzD
**FileAccess.java oPk2ac
*//文件访问(定位，写) L/%3_,
package NetFox; ]r$S{<
import java.io.*; 09_3`K.*
Up`$U~%-
n/pM[gI
public class FileAccessI implements Serializable{ )U>q><
isj<lnQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *P$5k1
RandomAccessFile oSavedFile; r}WV"/]p
long nPos; }{ pNasAU
ykRKZYfsw(
D(~6h,=m
public FileAccessI() throws IOException yT-m9$^v
{ G-Sw`HHo
this("",0); Pgr>qcbql
} W`eYd|+C
*Y9"-C+
}qmZ
public FileAccessI(String sName,long nPos) throws IOException *Mg=IEu-6[
{ Zr;.`(>
oSavedFile = new RandomAccessFile(sName,"rw"); }Da8S|)H
this.nPos = nPos; ro}plK(<WQ
oSavedFile.seek(nPos); 'iXjt MX
} $$A{|4,aI
9C-F%te7
w<J$12 "p+
public synchronized int write(byte[] b,int nStart,int nLen) Y_p
{ A8e b{qv
int n = -1; {u9(qd;;
try{ Z!G;q}zZ!
oSavedFile.write(b,nStart,nLen); zXbTpm
n = nLen; Gw~^6(Qu
} W5 fO1F
catch(IOException e) G&/}P$
{ !b rN)b)f
e.printStackTrace (); (4$lB{%
} BtBy.bR
uEVRk9nb
V F6OC4 K
return n; %Q1v8l.}
} M4nM%qRGQ
]B3 0d
}C2I9Cl
} 9 ?MOeOV8
+@Fy) {C7
Q7"KgqpQ3
/* /B|#GJ\\3
**SiteInfoBean.java >]T(}S~
*/ @]H&(bw
package NetFox; v^[tK2&v
gLl?e8[F
z;#}uC
public class SiteInfoBean { '[qG ,^f
]'~'V2Ey
^zsCF0
private String sSiteURL; //Site's URL w][ ;
private String sFilePath; //Saved File's Path L@CN0ezQs
private String sFileName; //Saved File's Name VG&|fekF
private int nSplitter; //Count of Splited Downloading File h^x7[qe
qLA
Ujq)h:`
public SiteInfoBean() 6st(s@>
{//nSplitter的缺省值为5 }! zjj\g^
//default value of nSplitter is 5 kJJQcjAP:
this("","","",5); wnt^WW=a[
} ;bP7|
~NU~jmT2
F3';oyy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) oJyC{G
{ Dih~5
sSiteURL= sURL; u+8_et5T
sFilePath = sPath; P4R.~J ;8
sFileName = sName; +n2x@ 0op
this.nSplitter = nSpiltter; d@8_?G}
3Y=T8Gi#
-lb}}z+/
} ^6J*yV%
+1h^9Y'
7@+0E2'
public String getSSiteURL() -cY/M~
{ dn%/SJC
return sSiteURL; ^Ud`2 OW;2
} "]zq<LmX
oY+RG|j@
P5] cEZ n
public void setSSiteURL(String value) yU .B(|
{ d{ OY
sSiteURL = value; {nj\dU
} ~)oC+H@{
P3lNns3
B: {bmvy
public String getSFilePath() G@,qO#5&
{ ~a/yLI"'g
return sFilePath; LjxTRtB_
} Zh3]bg5
Hb!Q}V+Kb8
J )@x:,o
public void setSFilePath(String value) 0qR;Z{k
{ ~jF5%Gu
sFilePath = value; 7J$ ^R6rh
} QI`Z[caF
(qohb0
Kpj0IfC,10
public String getSFileName() L$7v;R3
{ $Fd9iJ!k
return sFileName; KwpNS(]I
} .>CqZN,^
V4VTP]'n
$XT&8%|*7
public void setSFileName(String value) "b -KVZ
{ CHBCi) '6h
sFileName = value; J5|Dduv
} ly,d =
We9C9)0
?bN8h)>QQ8
public int getNSplitter() /l:3*u
{ Ev$?c9*>
return nSplitter; C(W?)6?
} 3R4-MK
S~Nx;sB
[@>Kd`!'
public void setNSplitter(int nCount) }>)"!p;t_
{ u!{P{C
nSplitter = nCount; W.0dGUi*
} ].:S!QO
} 2psLX
#( X4M{I
=A=er1~%
/* M-|4cd]6
**Utility.java ]9A9q<lZ
*/ M[TgNWl/[
package NetFox; $C^94$W
a*%>H(x
"v^Q !
public class Utility { dc%+f
gX6'!}G8]
Lxd*W2$3_
public Utility() LD^V="d
{ c&F"tLl
dwAju:-H
*K m%Vl
} !:e}d+F
atW;S99#
//线程睡眠 CS6,mX
public static void sleep(int nSecond) M@{GT/`Pf
{ =@{H7z(p&
try{ hc~--[1c:
Thread.sleep(nSecond); M}M.
} *"1]NAz+
catch(Exception e) \zgRzO'N
{ H={fY:%
e.printStackTrace (); 3go!P])
} xE4T\%-K
} xNq&_oY7
&\c$s
//日志 t{84ioJ"$
public static void log(String sMsg) 0W]Wu[k
{ ("H:T?4Qs
System.err.println(sMsg); n;O 3.2
} JLc\KVmF
_|H]X+|
G^ n|9)CVW
public static void log(int sMsg) iFga==rw
{ o+6Y/6Xp@
System.err.println(sMsg); m,)Re8W-
} @@!t$dD
} p3sz32RX
% J+'7'g
80:na7$)#
/* c#Ux{^ZE
**TestMethod.java )+\e+Ad}H
*/ $,'r} %
package NetFox; 2R|2yAh
bjD0y cB[
>I!dJH/gj
public class TestMethod { qK(?\t$
PksHq77
:vV?Yv%P)n
public TestMethod() 2+y4Gd 7
{ ///xx/weblogic60b2_win.exe )c+ZQq
try{ F>!fu.Ws
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +a;:7[%&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]9b*!n<z
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2BRY2EF
fileFetch.start(); C]eb=rw$
} +F+jC9j(<
catch(Exception e){e.printStackTrace ();} _(oJ8h(
=]etw
~~wz05oRG
} >f}rM20Vm
Xj|j\2$ 0
l_QpPo!a
public static void main(String[] args) F<G.!Y8!&
{ ;~xkT'
new TestMethod(); M62V NYt
} "4Anh1,js
} \s+<w3
点击下载更多相关资料