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)); UhB+c
} ?7\V)$00(&
for(int i=0;i<nEndPos.length-1;i++) UG1<Xfu|
{ ,f03TBD}
nEndPos = nStartPos[i+1]; l;F"m+B!$
} 3ML][|TR
nEndPos[nEndPos.length-1] = nFileLength; fif;n[<
} ^`H'LD
} /4{WT?j
^Z (cVg
s5,@=(,
//启动子线程 F`}'^>
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; " <bjS
for(int i=0;i<nStartPos.length;i++) 'CBwE&AL
{ X[z;P!U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ODJ"3 J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !G%!zNA S
nStartPos,nEndPos,i); tpI/Ibq
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m:_#kfC&K"
fileSplitterFetch.start(); "|\hTRQ
} V[ UOlJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g4W$MI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :?f<tNU$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Aez2n(yac
nEndPos = " + nFileLength); 4S(G366
// fileSplitterFetch[nPos.length-1].start(); lp*5;Ls'q
/Pjd"
H UJqB0D ?
//等待子线程结束 mQj#\<*
//int count = 0; eI-fH
//是否结束while循环 6Ga'_P:
boolean breakWhile = false; >iyNZ]."\
r$<!?Z
l,n_G/\
while(!bStop) 4DIU7#GG
{ k_g@4x1y*
write_nPos(); b~;:[ #
Utility.sleep(500); Y58H.P
breakWhile = true; '[ c-$X2Ak
-=-^rQx9
5N9Cd[4
for(int i=0;i<nStartPos.length;i++) s:<y\1Ay
{ e`Yj}i*bx]
if(!fileSplitterFetch.bDownOver) %+r(*Q+0$f
{ |\bNFnn(
breakWhile = false; hyxv+m[
break; Zl_sbIY
} HSud$(w
} e"@r[pq-{u
if(breakWhile) g.\b@0Uy'
break; E2Sj IR}
CfOyHhhKX
/}u:N:HA%
//count++; u`EK^\R
//if(count>4) J5b3r1~D"[
// siteStop(); ErN[maix#
} #h.N#{9
t{,$?}
>MJ%6A>
System.err.println("文件下载结束！"); 3 EAr=E]
} *b;)7lj0h
catch(Exception e){e.printStackTrace ();} /5%'q~
} yXkQ ,y
}[%F
!,-'wT<v
//获得文件长度 9f['TG,"
public long getFileSize() 6l|L/Z_6
{ l[ko)%7V
int nFileLength = -1; M"mvPr9
try{ "eoPG#]&
URL url = new URL(siteInfoBean.getSSiteURL()); "P.sKhuo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 02 FLe*zQ
httpConnection.setRequestProperty("User-Agent","NetFox"); (9bU\4F\
U>IsmF>m
*3^7'^j<
int responseCode=httpConnection.getResponseCode(); |yNyk7~
if(responseCode>=400) '>OEQU5-
{ ;E}&{w/My
processErrorCode(responseCode); 7|Vpk&.>
return -2; //-2 represent access is error ]Y & 2&
} ,>g(%3C
'bv(T2d~~
&WCVdZK:
String sHeader; 7d{xXJ-
q.:a4w J
6o#J
for(int i=1;;i++) 9U9ghWH8
{ ^=I[uX-3ue
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tIA)LF
//Utility.log(in.readLine()); vr>J$(F
sHeader=httpConnection.getHeaderFieldKey(i); *~`oA~-Q
if(sHeader!=null) Z(E.F,k
{ u`L*
if(sHeader.equals("Content-Length")) 11$v~<M
{ O[ans_8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4pDZ +}p
break; U:/_T>f%
} v@X[0J_8
} Mc
else JjAO9j%
break; kSJ:4!lFU
} Cn9MboXX
} 8BIPEY -I?
catch(IOException e){e.printStackTrace ();} c1]\.s
catch(Exception e){e.printStackTrace ();} ?s0")R&
jaTCRn3|<
*!EHs04
Utility.log(nFileLength); UR`pZ.U?
QD[l 6
|?fc]dl1]
return nFileLength; m<9W#
} WtSlD9 h
=2wy;@f
ku5g`ho
//保存下载信息（文件指针位置） el0W0T
private void write_nPos() a'@?c_y;$
{ K)oN^
try{ 1n ZE9;o
output = new DataOutputStream(new FileOutputStream(tmpFile)); LD5E
output.writeInt(nStartPos.length); xeHqC9Ou
for(int i=0;i<nStartPos.length;i++) -E!V;Tgc%U
{ #`Et{6WS
// output.writeLong(nPos); > cJX'U9
output.writeLong(fileSplitterFetch.nStartPos); -aMwC5iR@
output.writeLong(fileSplitterFetch.nEndPos); !FnH;
} 2TC7${^9}J
output.close(); =HvLuVc
} F9SIC7}uH
catch(IOException e){e.printStackTrace ();} j#XU\G
catch(Exception e){e.printStackTrace ();} (aH_K07
} 7<ES&ls_
q}R"
vCNYqa)m:
//读取保存的下载信息（文件指针位置） jZY9Lx8o
private void read_nPos() ;c>Rjg&[
{ 'uOp?g'7
try{ Ie;}k;?-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); seH#v
int nCount = input.readInt(); :!EOg4%i
nStartPos = new long[nCount]; WxLILh
nEndPos = new long[nCount]; ]+S.#x`#
for(int i=0;i<nStartPos.length;i++) pRdO4?l
{ &"svt2
nStartPos = input.readLong(); h:+>=~\
nEndPos = input.readLong(); ZjJEjw
} T+/Gz'
input.close(); 2\!.w^7'^T
} xH8nn3U
catch(IOException e){e.printStackTrace ();} :U;ZBs3
catch(Exception e){e.printStackTrace ();} 86@@j*c(@k
} )Nq$~aAm
yyHr. C
t UW'E
private void processErrorCode(int nErrorCode) Zt[1RMO
{ 4d3PF`,H`
System.err.println("Error Code : " + nErrorCode); yz2NB?)
} N|1k6g=0
m[u 6<C
Hw/1~O$T
//停止文件下载 Z)(C7,Xu
public void siteStop() C`x>)wm:
{ 'u.`!w '|L
bStop = true; an<tupi[E
for(int i=0;i<nStartPos.length;i++) L+QEFQ:r5
fileSplitterFetch.splitterStop(); @*l}2W
M|`%4vk>
4 ITSDx
} *-Y|qS%
} 0:nQGX!N
//负责部分文件的抓取 (85F1"Jp
**FileSplitterFetch.java ?P`]^#
*/ U]ouBG8/
package NetFox; Hj;j\R >2
+3t(kQ
$X-,6*
import java.io.*; `pN]Ykt
import java.net.*; qx53,^2
\"PlM!0du
mrd(\&EhA
public class FileSplitterFetch extends Thread { Ef$xum{
-D.6@@%Kc}
c#`Z[
String sURL; //File URL K=Fcy#,f
long nStartPos; //File Snippet Start Position E<&VK*{zcO
long nEndPos; //File Snippet End Position 6576RT
int nThreadID; //Thread's ID ~&4,w9b)j
boolean bDownOver = false; //Downing is over 0/(YH
boolean bStop = false; //Stop identical [?Aq#av
FileAccessI fileAccessI = null; //File Access interface 1/w['d4l!
NRq jn; ,+
UmQ 9_H7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException iQin|$F_O
{ yNY1g?E
this.sURL = sURL; rMf& HX
this.nStartPos = nStart; D@d/O
this.nEndPos = nEnd; +69sG9BA
nThreadID = id; 6eK18*j%H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D 7H$!(F>
} |'=R`@w~0
d%4!d_I<
jt-ayLq
public void run() KH2a 2
{ +l&ZN\@0X
while(nStartPos < nEndPos && !bStop) yZA}WTGe
{ HK5\i@G+<
YJXh|@LT
pt|u?T_+
try{ \nPa>2r
URL url = new URL(sURL); Scs \nF2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,p>=WX
httpConnection.setRequestProperty("User-Agent","NetFox"); ^^)D!I"cA,
String sProperty = "bytes="+nStartPos+"-"; =QOtag1;
httpConnection.setRequestProperty("RANGE",sProperty); @y)-!MHN(8
Utility.log(sProperty); RNp3lXf O
xC!,v 0&
qeSxE`E"
InputStream input = httpConnection.getInputStream(); x@Z?DS$)
//logResponseHead(httpConnection); #ra:^9;Es:
4 K{4=uU
&d9tR\}
byte[] b = new byte[1024]; z)yxz:E
int nRead; S#_i<u$$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) JTQ$p*2]
{ KDwjck"5;
nStartPos += fileAccessI.write(b,0,nRead); 8GV$L~i
//if(nThreadID == 1) [L] ca*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qnv9?Xh
} C-m OtI
6#KRI%adw`
2\lUaC#E
Utility.log("Thread " + nThreadID + " is over!"); RBJgQ<j8
bDownOver = true; '1|r+(q|2
//nPos = fileAccessI.write (b,0,nRead); 4U~[8U}g
} 4=>/x90y
catch(Exception e){e.printStackTrace ();} j!qO[CJJ
} ^'*9,.ltd
} 70mQ{YNN
B@=+Fg DD
VLA9&.*@
//打印回应的头信息 *pyi;
public void logResponseHead(HttpURLConnection con) b;Pqq@P|g
{ H)G ^ Y1
for(int i=1;;i++) ,cYU
{ uRh`qnL
String header=con.getHeaderFieldKey(i); h$G&4_O
if(header!=null) yx4B!U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j{0_K+B
Utility.log(header+" : "+con.getHeaderField(header)); TfDx> F$
else qeb:n$
break; |/Am\tk#13
} 0:@:cz=#*
} x0?8AG%
88$G14aXEk
's8NO Xlj
public void splitterStop() SVpvx`&kT
{ L8Z[Ly+_
bStop = true; /KO!s,Nk
} WhMr'l/e
'{@hBB+ D
@c,}\"(
} 5^t68 WOl
]m{;yOQdsC
KIps{_J[<
/* -P]J:7*0?\
**FileAccess.java VTa?y
*//文件访问(定位，写) KN'l/9.
package NetFox; |qE"60&"}
import java.io.*; )**k3u t4
JR<#el
3/H^YM @
public class FileAccessI implements Serializable{ c BQ|mA
{:$0j|zL1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WIb\+!
RandomAccessFile oSavedFile; +*WE<4"!6
long nPos; kzZtKN9Az
`zAV#
y@ J\h8_
public FileAccessI() throws IOException D9B?9Qt2[
{ :c"J$wT/
this("",0); I1=YSi;A
} hun LV8z
B08q/qi
f&bY=$iff
public FileAccessI(String sName,long nPos) throws IOException [Qa0uM#SU
{ s[)2z3
oSavedFile = new RandomAccessFile(sName,"rw"); 8XD9fB^
this.nPos = nPos; Z'6 o$Xv
oSavedFile.seek(nPos); >|KfO>
} JAj<*TB.%
[-bL>8
W1$B6+}Z0V
public synchronized int write(byte[] b,int nStart,int nLen) j_-$xz5-
{ - o$S=
int n = -1; 0I* ^VGZ
try{ _|D8~\y
oSavedFile.write(b,nStart,nLen); u`$,S&Er
n = nLen; %?J\P@
} 2/RK pl &
catch(IOException e) e<dFvMO
{ G'q7@d{'
e.printStackTrace (); d}3<nz,
} I&3L1rl3{*
F IDNhu
l]Jk }.
return n; m1a0uEA G
} >Y?B(I2e
R!lNm,i
aD8cqVhM3&
} |jJC~/WR
)I9AF,K
Y=sRVypJ
/* Mii-Q`.:
**SiteInfoBean.java Na=9ju
*/ VG*BAFs
package NetFox; I>k3X~cG
8s-RNA>7^
u{"o*udU
public class SiteInfoBean { EC&t+"=R
{cnya*
38b%km#
private String sSiteURL; //Site's URL 2/sD#vC
private String sFilePath; //Saved File's Path w&f8AY)#]4
private String sFileName; //Saved File's Name *E+2E^B
private int nSplitter; //Count of Splited Downloading File }OJ*o
`sQ\j Nu
@4^5C-
public SiteInfoBean() L^yQb4$&M
{//nSplitter的缺省值为5 E D*=8s2
//default value of nSplitter is 5 .21%~"dxJ
this("","","",5); >Bq;Z}EV
} 6_=qpP-?
JQYIvo1,Q
iaQ[}'6!$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :k6|-A2
{ k:4 Zc3
sSiteURL= sURL; 8jd<|nYnfc
sFilePath = sPath; 6%H8Qv
sFileName = sName; vC E$)z'"
this.nSplitter = nSpiltter; +"Ih'bb`j
v Q[{<|K
iC?s`c0B
} sqi~j(&\1
wXPNfV<(2
bM;yXgorU
public String getSSiteURL() >"jV8%!sM
{ ,pa,:k?
return sSiteURL; /%po@Pm#I
} Dx$74~2e
Ev0GAc1
Iwi>yx8
public void setSSiteURL(String value) .{k(4_Q?I
{ I+D`\OSL
sSiteURL = value; leiED'
} |xZDc6HDW
r(yJE1Wz
x5v^@_: jr
public String getSFilePath() 0(|R NV_
{ GC66n1- X
return sFilePath; _DMj)enH"
} B, xrZs
<Xm5re.
vY *p][$
public void setSFilePath(String value) }U7>_b2
{ 2n?\tOm(V
sFilePath = value; [POcO
} cx|[P6d
($E(^p% O
|(}uagfrd
public String getSFileName() Vm'ReH
{ >ly= O
return sFileName; w!:u|
} (sS[F-2R7
reM%GU
+6*oO|
public void setSFileName(String value) t"2WJ-1k}
{ <3P?rcd,5K
sFileName = value; &|%z!x6f
} I m_yY
c1wgb8
dS0G+3J&+E
public int getNSplitter() \>cZ=
{ 9XT6Gf56
return nSplitter; Mki(,Y|1~
} cy)L%`(7
sa#=#0yg
$MKx\qx}
public void setNSplitter(int nCount) 1(w0*`
{ ]WN{8
nSplitter = nCount; (loUO;S=
} fL83:<RK
} o1MbHBb
#Q 2$v;
o|]xj'
/* $msT,$NJ
**Utility.java b$PNZC8f
*/ ?-#w [J'6
package NetFox; ~W5fJd0
>m}.}g8
GJ%It.
public class Utility { @)<uQ S
z9h`sY~
xw%?R=&L
public Utility() eX?o4>
{ \5s!lv*&
-jC. dz
SnQ$
} jt3s;U*
cB.v&BSW
//线程睡眠 ed{z^!w4
public static void sleep(int nSecond) Mk@_uPm
{ zG [-n.
try{ &JfyXM[]
Thread.sleep(nSecond); k B2+Tr
} T%P0M*
catch(Exception e) rxP^L(q0*
{ VrF]X#\)
e.printStackTrace (); r2""p
} E'MMhlo
} gl]{mUZz}
~JC``&6E=}
//日志 {zVJlJKxs
public static void log(String sMsg) sB7DF<91
{ ]NTHit^EX
System.err.println(sMsg); R#1m_6I
} Fi7pq2
JG/sKOlA
ReSP)%oW
public static void log(int sMsg) HkEp}R
{ c%xxsq2n
System.err.println(sMsg); :+E>UzT
} AqN(htGvx
} v`wPdb
SvI
5n(p1OM2q
/* v+Mt/8
**TestMethod.java 2a? d:21 B
*/ rTmcP23]
package NetFox; WU=Os8gR
!*CL>}-,
DCwldkdJN
public class TestMethod { X^aujK^@
ig?]kZ
.'X$SF`
public TestMethod() P_b00",S
{ ///xx/weblogic60b2_win.exe !_x-aro3<
try{ P6IhpB59
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pdtK3Pf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N18Zsdrp
SiteFileFetch fileFetch = new SiteFileFetch(bean); A`OU}'v?L
fileFetch.start(); V]vk9M2q[l
} ;| \Ojuf
catch(Exception e){e.printStackTrace ();} Nk^#Sa?
:j9;P7&"?
JY>]u*=
} [8)Zhw$
M%$zor
66z1_lA
public static void main(String[] args) lHP[WO
{ j\Q_NevV
new TestMethod(); nnr(\r~
} yYF80mnJz
} bLf }U9
点击下载更多相关资料