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)); CUaI66
} O3PE w4yA
for(int i=0;i<nEndPos.length-1;i++) xm6cn\e
{ he;&KzEu
nEndPos = nStartPos[i+1]; N{ @B@]
} 7ae8nZ3&
nEndPos[nEndPos.length-1] = nFileLength; 1Y_Cd
} D}r,t_]Eb
} &+u) +<&;(
Yw vXSA
{Ug?k<h7|
//启动子线程 VZ5EV'D8!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ! jm>
for(int i=0;i<nStartPos.length;i++) PTXy:>]M
{ dd@qk`Zl&A
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K1AI:$H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )4vZIU#
nStartPos,nEndPos,i); q["CT&0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); PF+v[h;,
fileSplitterFetch.start(); y2bL!Y<s9
} _=Ed>2M)no
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {L$]NQdz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C0eP/d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", u[$ \ az7
nEndPos = " + nFileLength); '5\7>2fI
// fileSplitterFetch[nPos.length-1].start(); Mhc!v, D$
/f@VRME
^p?O1qTg
//等待子线程结束 RcIGIt
//int count = 0; E5(\/;[*`
//是否结束while循环 \$n?J(N
boolean breakWhile = false; eLXG _Qb"
03Pa; n
yJkERiJV
while(!bStop) "E =\Vz
{ #05#@v8.f
write_nPos(); =(Y 1y$
Utility.sleep(500); sS/#)/B
breakWhile = true; z;yb;),
?&W1lYY
]V\qX+K
for(int i=0;i<nStartPos.length;i++) {_ti*#
{ _R-[*ucq
if(!fileSplitterFetch.bDownOver) JDrh-6Zgj
{ Ch8w_Jf1yx
breakWhile = false; m&(yx|a4+
break; @|! 9~F
} &"]Uh
} C50&SrnBU1
if(breakWhile) a=}JW]
break; !mLQdkTE
U+gOojRy{
gU1E6V-Jm
//count++; R L&z\S
//if(count>4) 4X,fb`
// siteStop(); lIPy)25~
} ZS[(r-)$F
yDh(4w-~gk
6) {jHnk)
System.err.println("文件下载结束！"); /Ud<4j-
} Qwl=/<p1
catch(Exception e){e.printStackTrace ();} ns`|G;1vv
} 9i4!^DM_
~^jdiy5
)QS4Z{)U
//获得文件长度 'ap<]mf2
public long getFileSize() Z'sAu#C
{ vpR^G`/
int nFileLength = -1; d3Dw[4
try{ vowU+Y
URL url = new URL(siteInfoBean.getSSiteURL()); nk.m Gny
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0?kaXD
httpConnection.setRequestProperty("User-Agent","NetFox"); F&?55@b
`tZu~ n
=*EIe z*.x
int responseCode=httpConnection.getResponseCode(); .Y B}w
if(responseCode>=400) x;A"S
{ $50rj
processErrorCode(responseCode); D4 {?f<G0F
return -2; //-2 represent access is error .KiJq:$H
} &6!~Q,;K-
4u}"ng
c`:hEQs
String sHeader; ="E^9!
N[e QT
VrL==aTYXs
for(int i=1;;i++) !<9sOvka{
{ WT(inf[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kO3{2$S6
//Utility.log(in.readLine()); a^yBtb~,P
sHeader=httpConnection.getHeaderFieldKey(i); 3#fu;??1.
if(sHeader!=null) [Xp{ztGE
{ fQ>=\*b9x^
if(sHeader.equals("Content-Length")) |,zcrOo]
{ |$[WnYP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =+um:*a.
break; VAkZ@ u3'~
} _@es9
} ^X2U A{
else :00 #l]g0q
break; +<p?i]3CHe
} |~'D8 g:Ak
} emZ^d/A
catch(IOException e){e.printStackTrace ();} eIVCg-l}
catch(Exception e){e.printStackTrace ();} 3Cq/ o'
:,.g_@wvG
W}+f}/&l
Utility.log(nFileLength); V,,/}f'
uQy5t:!
-ya0!D
return nFileLength; C N9lK29F)
} L||_Jsu
Dd+ f,$
wg6![Uh
//保存下载信息（文件指针位置） "BB#[@
private void write_nPos() e@k`C{{C]o
{ GH%'YY3|
try{ AF{k^^|H
output = new DataOutputStream(new FileOutputStream(tmpFile)); Q;O\tl
output.writeInt(nStartPos.length); nJ/wtw
for(int i=0;i<nStartPos.length;i++) ]h (TZu
{ =~r?(u6d
// output.writeLong(nPos); m35Blg34
output.writeLong(fileSplitterFetch.nStartPos); YJgw%UVJ5m
output.writeLong(fileSplitterFetch.nEndPos); 'BT}'qN
} mT57NP
output.close(); $cO"1mu
} #plwK-tPR
catch(IOException e){e.printStackTrace ();} fgFBOpG%Gq
catch(Exception e){e.printStackTrace ();} eqbxf#H!
} ^G63GYh]y
7e&R6j
4)=LOGW
//读取保存的下载信息（文件指针位置） H[o'j@0
private void read_nPos() %UJ!(_
{ & -
try{ `n8) o%E9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &fYx0JT
int nCount = input.readInt(); jY-i`rJN
nStartPos = new long[nCount]; Auhw(b>}TW
nEndPos = new long[nCount]; L K9vvQz
for(int i=0;i<nStartPos.length;i++) *[*#cMZ
{ +MC>?rr_u
nStartPos = input.readLong(); woZ'T
nEndPos = input.readLong(); G8`q-B}q
} <\x/Y$jm0n
input.close(); XgKtg-,
} [!{*)4$6
catch(IOException e){e.printStackTrace ();} 8?W!U*0aS
catch(Exception e){e.printStackTrace ();} k]x64hgm
} ,_`\c7@
JnCY O^Qj
u;DF$
private void processErrorCode(int nErrorCode) ?mY )m +
{ ?n/:1LN,
System.err.println("Error Code : " + nErrorCode); u*[,W-R&
} 1W-t})!a
EF0{o_
D@qq=M
//停止文件下载 ^BjwPh4Z#
public void siteStop() EA75 D&>I
{ aEX;yy*
bStop = true; D`e!CprF
for(int i=0;i<nStartPos.length;i++) H's67E/>*
fileSplitterFetch.splitterStop(); {a_=4a
q=bJ9iJsq
5@j?7%_8
} ^`YSl*:
} Y,WcHE
//负责部分文件的抓取 M#})
**FileSplitterFetch.java ^/R@bp#<
*/ u4$d#0sA
package NetFox; {^9,Dy_D
65ijzZL;
u 8U>R=M
import java.io.*; 9R>A,x(
import java.net.*; G#duZNBdc
wx(|$2{h
x:;8U i"&B
public class FileSplitterFetch extends Thread { S3hJL:3c
4,FkA_k
N3vk<sr@
String sURL; //File URL h'UWf"d
long nStartPos; //File Snippet Start Position FlVGi3
long nEndPos; //File Snippet End Position lhQ*;dMj%"
int nThreadID; //Thread's ID H) q9.Jg
boolean bDownOver = false; //Downing is over bLu6|YB
boolean bStop = false; //Stop identical 3KB)\nF#%
FileAccessI fileAccessI = null; //File Access interface 3z&,>CEX
L4.yrA-]C%
k6[t$|lMy
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jSVb5P
{ u9mMkzgSkP
this.sURL = sURL; `mw@"
this.nStartPos = nStart; ^fnRzX
this.nEndPos = nEnd; ^ 9;s nr
nThreadID = id; q7 Uu 8JXF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O|7q,bEm^
} |[!xLqG
3p!R4f)GN
$6fHY\i#R
public void run() }qV4]*+{
{ ]o,)#/' $
while(nStartPos < nEndPos && !bStop) ?/#HTg)!B
{ n{4&('NRFP
pPQ]#v
5Odi\SJ&
try{ E6)FYz7x
URL url = new URL(sURL); !S(jT?'w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `mCcD
httpConnection.setRequestProperty("User-Agent","NetFox"); WHE*NWz>q
String sProperty = "bytes="+nStartPos+"-"; Htsa<tF
httpConnection.setRequestProperty("RANGE",sProperty); 4Iy\
Utility.log(sProperty); Vx* =
J=4S\0Z*
oVC~RKA*
InputStream input = httpConnection.getInputStream(); ;=h^"et
//logResponseHead(httpConnection); / d6mlQS
Yl-09)7s
hC6$>tl
byte[] b = new byte[1024]; BvX!n"QIb
int nRead; C?hw$^w7T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'Iu$4xo`[
{ dC,F?^
nStartPos += fileAccessI.write(b,0,nRead); :4Q_\'P
//if(nThreadID == 1) %gw0^^A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KsUsj3J
} !(SaE'
P?TFX.p7
GueqpEd2
Utility.log("Thread " + nThreadID + " is over!"); MHxv@1)K|Y
bDownOver = true; h ?p^DPo
//nPos = fileAccessI.write (b,0,nRead); u1]5qtg"
} $fnFi|-
catch(Exception e){e.printStackTrace ();} zyCl`r[}
} u:m]-'
} aNXu"US+Sp
)C|>M'g@v
rm"bplLZA
//打印回应的头信息 `86 9XE
public void logResponseHead(HttpURLConnection con) G3?8GTH
{ /ebYk-c
for(int i=1;;i++) $,h*xb.
{ #~p1\['|M
String header=con.getHeaderFieldKey(i); ~@sx}u
if(header!=null) %?RX}37K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {W0]0_mI(
Utility.log(header+" : "+con.getHeaderField(header)); IS!B$
else gCwg ;c-
break; ld2\/9+n
} @+xkd(RfN
} @~a52'\
c]xpp;%]
wF38c]r`\<
public void splitterStop() AK[9fxrE
{ t3bDi/m
bStop = true; -M[5K/[
} wetkmd
M}@^8
dmE-WS
} b/S4b
B>~E6j7[Mp
Re.fS6y$>
/* nGyY`wt&Rg
**FileAccess.java +F67g00T|
*//文件访问(定位，写) >:wk.<Z-
package NetFox; !})+WSs'"s
import java.io.*; $wX5`d1
]CHMkuP[k
F /t;y\)
public class FileAccessI implements Serializable{ {OQ sGyR?
$1UN?(r
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 AY *
RandomAccessFile oSavedFile; QR^pu.k@
long nPos; LU%g>?m.]
d5WE^H)E.
TYLf..i<
public FileAccessI() throws IOException J/ rQ42d
{ Mb/R+:C`
this("",0); (1TYJ. Z
} [vIO
Y4b"(ZhM_
%`gqV9a
public FileAccessI(String sName,long nPos) throws IOException d5u,x.R
{ +/UInAM
oSavedFile = new RandomAccessFile(sName,"rw"); ,sJ{2,]~
this.nPos = nPos; |r3eq4$Am
oSavedFile.seek(nPos); ,,,5pCi\
} L-=^GNh
az19-QIcg
[c3hwogf:
public synchronized int write(byte[] b,int nStart,int nLen) LWIU7dw
{ U8.DPRa
int n = -1; [%bshaY:
try{ QMkLAZ
oSavedFile.write(b,nStart,nLen); =P2T&Gb
n = nLen; f)gA.Rz
} w+ _'BU1#
catch(IOException e) B%r)~?6DM
{ _YbHnb
e.printStackTrace (); WlG/7$
} Bv/v4(G5g
WXGLo;+>I
BDcl1f T
return n; ?2.<y_1
} F1MPo;e
1k "*@Z<
vY.p~3q :)
} i\,#Z!
gKBcD\F
vbh\uv&
/* LoNz 1KJL
**SiteInfoBean.java Tw|=;m
*/ -KOE2f
package NetFox; $'kIo*cZ
X;zy1ZH
, gz:2UY#
public class SiteInfoBean { -S9$C*t
<51(q_f
6i>xCb
private String sSiteURL; //Site's URL +vZ-o{}.jO
private String sFilePath; //Saved File's Path ?$8OVq.w,
private String sFileName; //Saved File's Name Ue~M.LZb
private int nSplitter; //Count of Splited Downloading File /z~;.jRg
G9^!= v@
C3WqUf<8`{
public SiteInfoBean() 'rU5VrK
{//nSplitter的缺省值为5 Fe`$mtPu.
//default value of nSplitter is 5 K]Ed-Tz8QZ
this("","","",5); s6!aGZ
} q[**i[+%
c1!h;(&
bIwt#:v
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) vvdC.4O
{ L?<V KT
sSiteURL= sURL; &o:wSe
sFilePath = sPath; B!rY\ ?W
sFileName = sName; 1j3mTP
this.nSplitter = nSpiltter; BWz*!(
O,XVA
If2f7{b
} |a/"7B|?\
s#64NG
q9F(8-J
public String getSSiteURL() M~p=OM<
{ D+#QQH
return sSiteURL; M)( 5S1ndq
} lP\7=9rh^x
2["bS++?
$oe:km1-D
public void setSSiteURL(String value) ^JJ*pT:
{ Pr<.ld\
sSiteURL = value; .$L'Jt2X
} 4*G#fW-
Z^>{bW
+{4ziqYj
public String getSFilePath() 5fDVJE "9"
{ b~WiE?
return sFilePath; Ihw^g<X
} /87?U; |V
-Wb/3X
nV@k}IJg:?
public void setSFilePath(String value) \l"1Io=
{ )zf&`T
sFilePath = value; n2Q~fx<6%
} :l'61$=
iQ~;to;Y
Q+$+{g-8
public String getSFileName() -}AAA*P
{ +.! F]0ju
return sFileName; 6f v{?0|
} JS1$l+1
[>U'P1@ql
+Vl\lL -
public void setSFileName(String value) 5RrzRAxq
{ mG*[5?=r
sFileName = value; fb0i6RC~&
} /5b,&
]4^9Tw6 _b
]DHB'NOh,
public int getNSplitter() 2_'{f1bVxz
{ 2? 9*V19yu
return nSplitter; airg[dK
} JPJ&k(P
b1>zGC^|
Ka%u#};
public void setNSplitter(int nCount) 4! ]28[2B6
{ He @d~9M
nSplitter = nCount; ve|ig]$5g<
} c5Fl:=h
} &Azfpv
>1q W*
*DfwTbg|
/* jrJ!A(<)
**Utility.java E]Dcb*t
*/ ]06orBV
package NetFox; Wwo'pke
%P@V7n
HG kL6o=
public class Utility { 'b1k0 9'
/&1FgSARK
.S4c<pMap
public Utility() E "9`
{ ~gZ"8frl
m ioNMDG
d7(g=JK<
} X$mCn#8m
]c/k%]o~
//线程睡眠 F%|F-6
public static void sleep(int nSecond) :qlcN@_
{ !C]2:+z-MF
try{ P)D2PVD
Thread.sleep(nSecond); 9W5~I9%
} 'LC-/_g
catch(Exception e) KNvvYwFH]
{ )DG>omCY
e.printStackTrace (); ~|CWy
} ZhvZe/
} {"e)Jj_=
t_ju[xL5B
//日志 kz30! L
public static void log(String sMsg) L<dJWxf?D
{ XWd;-%`<
System.err.println(sMsg); ;zF3e&e(
} [T}Lq~
@}{lp'8FYi
SLsw '<
public static void log(int sMsg) PPpq"c
{ ue8"_N
System.err.println(sMsg); r3;@
} uPhL?s{
} :)*+aS"
sV']p#HK0
Q%T[&A}3B
/* or<n[<D-C
**TestMethod.java NoAgZ{))
*/ Ga$J7R
package NetFox; Z~S%|{&Br
,h<xL-
; <NK
public class TestMethod { tg~@(IT}j
-Z(='A
rGDx9KR4K!
public TestMethod() D\H;_k8
{ ///xx/weblogic60b2_win.exe T1~G{@"
try{ ATG;*nIP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *DUP$@}k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o)]mJb~XG-
SiteFileFetch fileFetch = new SiteFileFetch(bean); o'?[6B>oj
fileFetch.start(); OaH1xZNOC`
} &#< M o
catch(Exception e){e.printStackTrace ();} '_~qAx@F#c
)Vf!U"
\?_M_5Nb
} YZdV0-S
cF V[k'F
k[Ue}L|
public static void main(String[] args) JYw_Z*L=m
{ ]#sF pWI[N
new TestMethod(); U_KCN09
} p6c&vEsNj
} ZJf:a}=h
点击下载更多相关资料