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)); Qu*1g(el!o
} <EX7WA
for(int i=0;i<nEndPos.length-1;i++) |(IO=V4P
{ Rhgj&4
nEndPos = nStartPos[i+1]; h,t|V}Wb
} .=RlOK
nEndPos[nEndPos.length-1] = nFileLength; ?2J?XS>
} x!TZ0fq0
} t={0(
q%3<Juq~$
0NE{8O0;Fr
//启动子线程 ~9o6 W",
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |WQ9a' '
for(int i=0;i<nStartPos.length;i++) O_,O,1
{ [uuj?Rbd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s'I)A^i+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7v~j=Z>
nStartPos,nEndPos,i); 'VnwG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ggm` ~fS
fileSplitterFetch.start(); -$8.3\6h
} XJ\hd,R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W.}].7}h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a=]Wzlz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LgqGVh3\s
nEndPos = " + nFileLength); D#rrW?-z
// fileSplitterFetch[nPos.length-1].start(); C*~aSl7
)$M,Ul
5mB]N%rfW%
//等待子线程结束 i2,U,>.
//int count = 0; 1JS2SxF
//是否结束while循环 7!V@/S}7
boolean breakWhile = false; Z|6{T
d.F)9h]XHO
?Hz2-Cn
while(!bStop) &_-](w`
{ Mhpdaos
write_nPos(); $g8}^1
Utility.sleep(500); y.a]r7
breakWhile = true; 5N/Lk>p1u
I*)VZW
>9K//co"of
for(int i=0;i<nStartPos.length;i++) #;r]/)>
{ 0&w0aP`Y
if(!fileSplitterFetch.bDownOver) Ww9;UP'G
{ j BS4vvX?
breakWhile = false; %e%7oqR?
break; _^!vCa7f
} o+?@5zw-&
} htJuGfDx1
if(breakWhile) NP t(MFK\
break; m2bDHQ+
6qp5Xt+
y;`eDS'0.N
//count++; wz(K*FP
//if(count>4) 'imU`zeo
// siteStop(); p]|LV)R n
} JJk#,AP
a:!uORQby
D_D,t8_Y
System.err.println("文件下载结束！"); /XpSe<3
} !c(QSf502
catch(Exception e){e.printStackTrace ();} d,#.E@Po
} b5`KB75sbo
c.K =(y*
FvImX
//获得文件长度 W4(?HTWZ
public long getFileSize() C8b''9t.
{ [1Dm<G u@
int nFileLength = -1; MWwJzVL8
try{ 3(_!`0#F%
URL url = new URL(siteInfoBean.getSSiteURL()); _n O.-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2<W&\D o@
httpConnection.setRequestProperty("User-Agent","NetFox"); HkjEiU
'p}`i/
$Xf(^K
int responseCode=httpConnection.getResponseCode(); G2Qjoe`Uc
if(responseCode>=400) !k&)EWP?
{ ~l4f{uOD>]
processErrorCode(responseCode); p8>%Mflf
return -2; //-2 represent access is error &r_uQbx
} fEqC] *s
KCqqJ}G
x7ATI[b[
String sHeader; NPU^)B
W'$kZ/%[
Uene=Q6>
for(int i=1;;i++) S`g;Y '
{ <|F-Dd
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g:~+Pe
//Utility.log(in.readLine()); TipHV;|e
sHeader=httpConnection.getHeaderFieldKey(i); Z7#7N wy4
if(sHeader!=null) Os&1..$Nb
{ o}D![/
if(sHeader.equals("Content-Length")) 9YKDguG
{ %J P!{mqj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Da,Tav%b
break; 8 njuDl
} X#J6Umutm
} L(o#4YH}>J
else gA:TL{X0
break; bx;f`8SN
} tbur$00
} {*xBm#
catch(IOException e){e.printStackTrace ();} ejcwg*i
catch(Exception e){e.printStackTrace ();} ~ =.CTm]vf
$$gtZ{ukQ
0s%6n5>
Utility.log(nFileLength); SGf9U^ds
P;U@y"s
aqL<v94wX
return nFileLength; YKx 1NC
} [MmM9J["
g9V.13k
d6b.zP
//保存下载信息（文件指针位置） uQp_':\k
private void write_nPos() -u6#-}S
{ UKs$W`
try{ g [L
output = new DataOutputStream(new FileOutputStream(tmpFile)); htHv&
output.writeInt(nStartPos.length); n`<S&KP|
for(int i=0;i<nStartPos.length;i++) eV;me>,
{ G11cNr>*
// output.writeLong(nPos); 3M*Y= ?pI
output.writeLong(fileSplitterFetch.nStartPos); [j0w\{
output.writeLong(fileSplitterFetch.nEndPos); "$@,n7k
} fM":f| G
output.close(); xrI}3T
} iZTa>@
catch(IOException e){e.printStackTrace ();} yYX :huw
catch(Exception e){e.printStackTrace ();} <Cq"| A
} h$&rE@N|
FAtWsk*pgY
{hd-w4"115
//读取保存的下载信息（文件指针位置） OmNn,PCl8
private void read_nPos() -Enbcz(B
{ I~RcOiL)
try{ P9yw&A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #s^s_8#&e
int nCount = input.readInt(); cjT[P"5$
nStartPos = new long[nCount]; sp{j!NSL
nEndPos = new long[nCount]; `o-*Tr
for(int i=0;i<nStartPos.length;i++) 6\`DlUn'*
{ ^x3EotQ\
nStartPos = input.readLong(); z93nYY$`Y
nEndPos = input.readLong(); 1v]t!}W:6
} W-Of[X{<
input.close(); yWuIu>VJ
} 6/7F">@j
catch(IOException e){e.printStackTrace ();} G"Pj6QUva
catch(Exception e){e.printStackTrace ();} u}CG>^0C
} :uvc\|:s
<Kp+&(l,l
~XQ$aRl&
private void processErrorCode(int nErrorCode) NcM3P G
{ XGk}e4;_
System.err.println("Error Code : " + nErrorCode); Fwv\pJ}$
} Zd XKI{b
nKu(XgFv
x!+Z{x
//停止文件下载 }200g_^
public void siteStop() ua:9`+Dff
{ m5qCq9Y
bStop = true; /j %_t
for(int i=0;i<nStartPos.length;i++) d+1x*`U|
fileSplitterFetch.splitterStop(); gvr]]}h:O
.+uVgSN
am(#Fa
} J/[7d?hI/
} \E&thp
//负责部分文件的抓取 JP%RTGu
**FileSplitterFetch.java jrcc
*/ Rk{$S"8S_
package NetFox; @Yarz1
`skH-lk,
$w`veP
import java.io.*; B3.X}ys#
import java.net.*; `&,_xUA
s kY0\V
H<z30r/-w
public class FileSplitterFetch extends Thread { w3d\0ub
j]Ua\|t
'tSnH&c
String sURL; //File URL Q'C4pn@
long nStartPos; //File Snippet Start Position <G}m#
long nEndPos; //File Snippet End Position 7YD\ !2b
int nThreadID; //Thread's ID _KxX&THaj
boolean bDownOver = false; //Downing is over i8eA_Q
boolean bStop = false; //Stop identical {[lx!QF 8&
FileAccessI fileAccessI = null; //File Access interface V^WQ6G1
%|bN@@
7_7xL(F/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pKYLAt+^>
{ BArJ"t*/z
this.sURL = sURL; 3l+|&q[v
this.nStartPos = nStart; 0@w&J9yG
this.nEndPos = nEnd; 8z0Hx
nThreadID = id; 6ku8`WyoF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9?!u2 o
} d(\1 }l
m]e0X*Kg
vj(@.uU)
public void run() ec#_olG%
{ c%b\CP\)W
while(nStartPos < nEndPos && !bStop) du8!3I
{ Cl{{H]QngX
Bd QQ9$@5
VAt>ji7c
try{ QdirE4W
URL url = new URL(sURL); g\qX7nIH?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jigbeHRy
httpConnection.setRequestProperty("User-Agent","NetFox"); WEps.]s
String sProperty = "bytes="+nStartPos+"-"; }il%AAI9}r
httpConnection.setRequestProperty("RANGE",sProperty); cS5w +`,L
Utility.log(sProperty); zK,~37)\
"wF*O"WQo
C\J@fpH(t`
InputStream input = httpConnection.getInputStream(); #'#4hJ*YC
//logResponseHead(httpConnection); Dn: Yi8=
VDPxue
H]U"+52h
byte[] b = new byte[1024]; $=7H1 w
int nRead; U:J /\-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZIDFF
{ D. 77WjwQ
nStartPos += fileAccessI.write(b,0,nRead); F6~b#Jz&i
//if(nThreadID == 1) +$'e4EwqV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7Y4%R`9H
} l#mtND3
]}5`7
Q-:Ah:/
Utility.log("Thread " + nThreadID + " is over!"); _AVy:~/
bDownOver = true; +V6j`
//nPos = fileAccessI.write (b,0,nRead); rknzo]N,
} Qz'O{f
catch(Exception e){e.printStackTrace ();} J&(
} p$B)^S%0i
} ws#hhW3qK
l DgzM3
h)"'YzCt
//打印回应的头信息 zj%cd;
public void logResponseHead(HttpURLConnection con) 9]"\"ka3>
{ bx1G CD
for(int i=1;;i++) H+nr5!`kz
{ Z=0iPy,m>
String header=con.getHeaderFieldKey(i); {|G&W^`
if(header!=null) u|(aS^H=q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -=@K%\\~5
Utility.log(header+" : "+con.getHeaderField(header)); ><MGZ?-N
else O2/%mFS.
break; H3W_}f
} x/pC%25
} w($XEv;
KwY`<t1lA;
$cyLI+uz|
public void splitterStop() Uy:@,DW
{ &mCs%l
bStop = true; ( ?atGFgu
} *4zoAslU1
h\Z3yAYd
hLu&lY
} 4mki&\lw`
>6n@\n
BASO$?jf4
/* N)`tI0/W
**FileAccess.java x*3@,GmZl
*//文件访问(定位，写) ]%b0[7[
package NetFox; ?U7&R%Lh`
import java.io.*; FuIWiO(
Z#H@BWN7
s9^"wN YQ
public class FileAccessI implements Serializable{ xKRfl1
F^4*|g
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,"4X&>_f
RandomAccessFile oSavedFile; fJ,8g/f8
long nPos; F[Qsv54
C6Um6X9/i
ZS07_6.~
public FileAccessI() throws IOException @`#OC#
{ P1M|f4*
this("",0); +:j4G^V
} fo/(()
qg/Y;tGSx
\Qe'?LRu{
public FileAccessI(String sName,long nPos) throws IOException x'VeL|
{ r%OrH-T
oSavedFile = new RandomAccessFile(sName,"rw"); cj,&&3sbV
this.nPos = nPos; &1\u#LU
oSavedFile.seek(nPos); LA(f]Xmc
} XyN`BDFi
yTMGISX5
?)i6:76(
public synchronized int write(byte[] b,int nStart,int nLen) gME:\ud$
{ 9 ayH:;
int n = -1; O% j,:t'"
try{ So3,Z'z=
oSavedFile.write(b,nStart,nLen); C{lB/F/|!
n = nLen; 7!]k#|u
} 6'3Ey'drH
catch(IOException e) dA3`b*nC
{ /jn:e"0~
e.printStackTrace (); J-HabHv
} G5C#i7cpm
JC1BUheeb
Y+S~b
return n; sZ\i(eIU
} ^^W`Lh%9
dW] Ej"W
!YuON6{)
} qX}dbuDE"P
`0/gs
k;9#4^4(
/* O;.d4pO(tC
**SiteInfoBean.java I+-Rs2wb
*/ IrVM|8vT3
package NetFox; vwSX$OZ
Fp* &os
Av\0GqF
public class SiteInfoBean { HvL9;^!
*>R/(Q
l-JKcsM
private String sSiteURL; //Site's URL 'JXN*YO
private String sFilePath; //Saved File's Path ?j ;,q
private String sFileName; //Saved File's Name OmQuAG ^\x
private int nSplitter; //Count of Splited Downloading File oD|+X/FK
B@:XC&R^
`jl. f
public SiteInfoBean() y[Fw>g1`q
{//nSplitter的缺省值为5 $ET/0v"V
//default value of nSplitter is 5 k/6Gj}l'o
this("","","",5); FL*w(Br.
} uvAy#,
)@};lmPR
9=sMKc%!-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) lqwJ F &
{ 3vEjf
sSiteURL= sURL; _16&K}<
sFilePath = sPath; m78MWz]Yo
sFileName = sName; Rg!aKdDl$
this.nSplitter = nSpiltter; U~QCN[gh
Ix l"'Q_z
~vvQz"
} ?PH}b?f4
xHR+((
$T@xnZ
public String getSSiteURL() :+X2>Lu$FA
{ M`f;-
return sSiteURL; 1]zyME
} %d~9at6-B
gEe W1:AB
A+Pm "|
public void setSSiteURL(String value) :7AauoI
{ mqfEs0~I
sSiteURL = value; =iQ`F$M
} Y_TL4
"#"Fp&Z7
e&VR>VJEA
public String getSFilePath() 0zkT8'v
{ c&iK+qvh{
return sFilePath; 4FP~+
} |'>E};D
_S7M5{U_
clU3#8P!=
public void setSFilePath(String value) 9jJ/ RXp
{ JCMEhI6d*
sFilePath = value; >@92K]J
} w1/T>o
MsVI <+JZ
?5+KHG*)
public String getSFileName() WSX@0A.&)
{ z]R!l%`
return sFileName; UEdl"FwM4
} I]j/ ab7>
77[;J
.]d tRH<
public void setSFileName(String value) y{},{~FA"
{ PX>\j&
sFileName = value; @):NNbtA
} Bo\dt@0;
R<YYf^y
8f`b=r(a>
public int getNSplitter() h,RUL
{ 0aN}zUf
return nSplitter; P+cFp7nC
} DWevg;_]$(
Gxt<kz
nfPl#]ef*
public void setNSplitter(int nCount) {UVm0AeUq
{ JnKbd~
nSplitter = nCount; 38.J:?Q
} U=<.P;+f9
} -W"0,.Dvg
x~Esu}x7
e, 3(i!47
/* *,=+R$
**Utility.java q\Io6=39x
*/ d+| !6
package NetFox; +!Gr`&w*)
\:)o'-
>"My\o
public class Utility { 2ZIY{lBe
jm!C^5!
af5`ktx
public Utility() /xbF1@XtL
{ ;.[$
*Zo o
|~vQ0D
} GZ>% &^E
^T1-dw(
//线程睡眠 }u*@b10
public static void sleep(int nSecond) YD>>YaH_3@
{ zbKW.u]v
try{ w*R-E4S?2
Thread.sleep(nSecond); Y8xnvK*
} r{3`zqo
catch(Exception e) Xv(9 YhS
{ \36;csu
e.printStackTrace (); uz2s-,
} v/6,eIz
} CoN/L`.SN
D{d$L9.
//日志 COJ!b
public static void log(String sMsg) Rm1`D
{ CO+jB
System.err.println(sMsg); .7^-*HT}
} r4>I?lD
93eqFCF.
8 =Lv7G%
public static void log(int sMsg) L/+J|_J)
{ ,^Srd20
System.err.println(sMsg); %H~gN9Vn#@
} #\;w::
} s7.*o@G
; SM^
13az[
/* YD.^\E4o
**TestMethod.java :|mkI#P.
*/ :pu{3-n.
package NetFox; %hb5C 4q
tLXw&hFk`g
4'=N{.TtO
public class TestMethod { \uPTk)oaB
>o=p5#{
EQhV}9
public TestMethod() #C7j|9Ew1]
{ ///xx/weblogic60b2_win.exe CXFAb1m
try{ P&^7wud-sb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,(=]6V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); diLl>z
SiteFileFetch fileFetch = new SiteFileFetch(bean); lH>XIEj
fileFetch.start(); twS3J)UH
} 6N)1/=)
catch(Exception e){e.printStackTrace ();} :P1c>:j[
meD (ja
`v{X@x
} =eLb"7C#0
OYy !4Fp
'U0I.x(
public static void main(String[] args) 3pH`]m2
{ A:J{
new TestMethod(); Xkm2C)
} -d)n0)9
} u@'zvkb@
点击下载更多相关资料