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)); r1!]<=&\
} GP,xGZZ
for(int i=0;i<nEndPos.length-1;i++) eVx &S a
{ #Ies yNKZ
nEndPos = nStartPos[i+1]; y9'F D5\s
} Q`4]\)Dp
nEndPos[nEndPos.length-1] = nFileLength; c-, 6k
} KJLK]lf}d
} ko<iG]Dv'
-ipfGb
zMI0W&P M
//启动子线程 ( O>oN~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OJH:k~]0!
for(int i=0;i<nStartPos.length;i++) 6"UL+$k
{ dS[="Set
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H@R2mw
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fpK`
nStartPos,nEndPos,i); ]p.eFYDh7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T1}9^3T?{
fileSplitterFetch.start(); ^"?b!=n!
} }{(|^s=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9v2(cpZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hm5A@Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )xMP
nEndPos = " + nFileLength); 8;r7ksE~
// fileSplitterFetch[nPos.length-1].start(); Q, !b
>5|;8v-r
x# &ZGFr~
//等待子线程结束 At#'q>Dn
//int count = 0; rH<iUiA?O
//是否结束while循环 $CYB&|d
boolean breakWhile = false; 8(Y=MW;g
95G*i;E
V,@Y,
while(!bStop) 9u\&kQxqD
{ vs)1Rm
write_nPos(); @Fl&@ $
Utility.sleep(500); 4gNF;
breakWhile = true; Cq0S8Or0
H@8g 9;+
UkY `&&ic
for(int i=0;i<nStartPos.length;i++) &xwAE*}
{ }Pj3O~z
if(!fileSplitterFetch.bDownOver) 1jhGshhp
{ 1K;i/
breakWhile = false; $*Q_3]AY]
break; $K,6!FyBa
} ^5l4D3@E
} CbA2?(1o1
if(breakWhile) $ZPiM
break; 5^\f[}
QzQTE-SQ
NNQro)Lpe
//count++; AjQ^ {P
//if(count>4) t7%!~s=,M
// siteStop(); 7 vS]O$w<4
} B0:[3@P7
Q(}TN,N
~!,Q<?
System.err.println("文件下载结束！"); <p'~$vK
} 9%?'[jJ
catch(Exception e){e.printStackTrace ();} h69: Tj!
} \c! LC4pE
FH'jP`
N>fC"
//获得文件长度 xwH+Q7O&l
public long getFileSize() SRN:!-
{ !S/hH%C
int nFileLength = -1; RPvOup
try{ !@_( W
URL url = new URL(siteInfoBean.getSSiteURL()); !8|]R
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); up~l4]b+
httpConnection.setRequestProperty("User-Agent","NetFox"); X`ifjZ9}d
t:X[Blw3$
*6)u5
int responseCode=httpConnection.getResponseCode(); m4@y58n=
if(responseCode>=400) H]. 4~ 8
{ Hy<4q^3$G
processErrorCode(responseCode); ] =jnt
return -2; //-2 represent access is error 3:rH1vG.m
} Qhnz7/a9
>8V;:(nt
.,K?(O4AY
String sHeader; ,~Y5vnaOQ
b&g9A{t
$ ;/Ny)"
for(int i=1;;i++) &Z+a (
{ )>ed6A1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [|2uu."$
//Utility.log(in.readLine()); p;VqkSQ76
sHeader=httpConnection.getHeaderFieldKey(i); N,w;s-*
if(sHeader!=null) qVFz-!6b
{ |67j__XC
if(sHeader.equals("Content-Length")) U/M(4H3>H
{ x7J|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rbnu:+!
break; UcMe("U
} C"/]X
} N1I1!!$K;%
else [Bp[=\
break; 5FHpJlFK,
} $2F*p#l(<Z
} :&dY1.<N+
catch(IOException e){e.printStackTrace ();} j>M 'nQ,;d
catch(Exception e){e.printStackTrace ();} &b}!KD1
|,]#vcJP#b
*?gn@4Ly
Utility.log(nFileLength); "w`f>]YLA
>]=1~sF
I0O)MR<
return nFileLength; Zg7~&vs$
} Y}"|J ~
R,A|"Q
p]:~z|.Ba
//保存下载信息（文件指针位置） g~%=[1
private void write_nPos() O'm&S?>
{ @]dN
try{ +*g[hRw[
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5.xvOi|.
output.writeInt(nStartPos.length); <27B*C M
for(int i=0;i<nStartPos.length;i++) h^$>{0"
{ dH!k{3bL
// output.writeLong(nPos); @6i^wC
output.writeLong(fileSplitterFetch.nStartPos); VVJhQbP
output.writeLong(fileSplitterFetch.nEndPos); C9Fc(Y?_
} G#Z%jO-XN
output.close(); x#|P-^
} T}2a~
catch(IOException e){e.printStackTrace ();} "G|Gyc
catch(Exception e){e.printStackTrace ();} 2?ZHWS>U
} lw? f2_fi
w"-bO ~5h
V/|Ln*rm
//读取保存的下载信息（文件指针位置） t9m:E
private void read_nPos() E[LXZh
{ gi:;{
try{ tF&%7(EU3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uGJeQ
int nCount = input.readInt(); \XMl8G
nStartPos = new long[nCount]; Lq LciD
nEndPos = new long[nCount]; )TM![^d
for(int i=0;i<nStartPos.length;i++) N{P (ym2yR
{ 1_/\{quE
nStartPos = input.readLong(); D}!U?]la&
nEndPos = input.readLong(); {C*mn!u
} (7}v}3/
input.close(); Q-}oe Q
} 3Du&KZ
catch(IOException e){e.printStackTrace ();} u!nt0hS
catch(Exception e){e.printStackTrace ();} I_#)>%H
} UNYU2ze'
y~1UU3k5
Ft`#]=IS
private void processErrorCode(int nErrorCode) pWps-e
{ e7/J:n$
System.err.println("Error Code : " + nErrorCode); GG;M/}E9
} .6$ST Ksr
9A3Q&@,
&)fPz-s
//停止文件下载 X~G"TT$)
public void siteStop() x`%;Q@G
{ tq@<8?
bStop = true; LiQs;$V
for(int i=0;i<nStartPos.length;i++) IwFg1\>
fileSplitterFetch.splitterStop(); ,X\z#B
J;"XRE[%5
1 EC0wX
} &.7\{q\(
} -mX _I{BJ
//负责部分文件的抓取 15U=2j*.b
**FileSplitterFetch.java =q5A@!D
*/ G!OD7:
package NetFox; )KBv[|
FNmIXpAn*@
<`|}bt
import java.io.*; K~,,xsy,G&
import java.net.*; o?p) V^7
}tv-
`p#A2ApA
public class FileSplitterFetch extends Thread { *TE6p
7GK| A{r
LUo3y'
String sURL; //File URL .Ji r<"*<
long nStartPos; //File Snippet Start Position P$]Vb'Fz
long nEndPos; //File Snippet End Position g-}Vu1w0{6
int nThreadID; //Thread's ID ,fET.s^|U
boolean bDownOver = false; //Downing is over ,Z>RvLl
boolean bStop = false; //Stop identical _7$j>xX
FileAccessI fileAccessI = null; //File Access interface 0yAvAx
Jz:d\M~j5
s977k2pp-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException lrq !}\aX
{ 2U|Nkm
this.sURL = sURL; *GRhZ~U
this.nStartPos = nStart; Ju+@ROZ
this.nEndPos = nEnd; yg\A&0I
nThreadID = id; O%c6vp7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~~5kAY-
} 8%`Sx[
u0XGtu$4
<,rjU*"
public void run() {b/AOR o
{ Z"!C
while(nStartPos < nEndPos && !bStop) M"p$9t
{ OIewG5O
/~ V"v"7E
rKJ%/7m
try{ Uut,cQ". d
URL url = new URL(sURL); v S%+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e@8I%%V,
httpConnection.setRequestProperty("User-Agent","NetFox"); },i?3dSvl
String sProperty = "bytes="+nStartPos+"-"; te:"1:e
httpConnection.setRequestProperty("RANGE",sProperty); D;d;:WT5
Utility.log(sProperty); )2^OBfl7
31b-r[B{%
jjl4A}*0
InputStream input = httpConnection.getInputStream(); )-jvp8%BK
//logResponseHead(httpConnection); "n]B~D
%&gx@ \v
&# @1n
byte[] b = new byte[1024]; -h.YQC`
int nRead; B0R[f
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WUa-hm2:
{ Brpin
nStartPos += fileAccessI.write(b,0,nRead); eyAg\uuih
//if(nThreadID == 1) M $e~Rlw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MQG$J!N
} *Z/B\nb
" *Ni/p$I
9m6w.:S
Utility.log("Thread " + nThreadID + " is over!"); /pb7
bDownOver = true; #Wc)wL-Tg
//nPos = fileAccessI.write (b,0,nRead); bJBx~
} 3`e1:`Hu
catch(Exception e){e.printStackTrace ();} IRS^F;)
} }qlz^s
} =e._b 7P
R [uo:.
~Kb(`Px@
//打印回应的头信息 =G=.THRUk
public void logResponseHead(HttpURLConnection con) i:[B#|%
{ d1E~H]X4
for(int i=1;;i++) 9d2$F9]:o
{ R9#Z=f,
String header=con.getHeaderFieldKey(i); r`7`f xe
if(header!=null) wk5a &
//responseHeaders.put(header,httpConnection.getHeaderField(header)); `>#X,Lw$g
Utility.log(header+" : "+con.getHeaderField(header)); <M\Z}2d
else }y[o[>
break; {O^1WgGc[
} 5 !NPqka}.
} ^NnZYr.
KR522YW
uNRGbDMA=
public void splitterStop() MPGQ4vi&
{ 7rr5$,Mv
bStop = true; 5SKu\H\
} fO(.I
pxY5S}@
=_,OucKkYG
} :YV!;dKJ
xHL{3^
+zw<iB)J
/* =8J\;h
**FileAccess.java hQet?*diU
*//文件访问(定位，写) 6Q wL
package NetFox; 49kY]z|"w
import java.io.*; u>? VD%
q&W#nWBV
a\MU5%}\
public class FileAccessI implements Serializable{ QR8F'7S
};KmMpBn
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m3|,c[M1
RandomAccessFile oSavedFile; U>I#f
long nPos; 9B%"7MVn
ipyO&v
.#}SK!"B
public FileAccessI() throws IOException >5N}ZIN
{ iL\\JuY
this("",0); >i ~zG6H
} sP&E{{<QTF
4^i*1&"
iFDQnt [t
public FileAccessI(String sName,long nPos) throws IOException +ypT"y
{ o1g[(zky
oSavedFile = new RandomAccessFile(sName,"rw"); +5HOT{wj
this.nPos = nPos; Mz{>vb
oSavedFile.seek(nPos); My1E@<
} nrxN_0 R%
CRx:3u!:
M,{F/Yu
public synchronized int write(byte[] b,int nStart,int nLen) :g\qj? o
{ d6n6= [*
int n = -1; |0bSxPXn!
try{ xGH%4J\
oSavedFile.write(b,nStart,nLen); 3NJH"amk
n = nLen; yqYX<<!V
} RoiMvrJQP
catch(IOException e) "vJADQ4F
{ Nyo6R9^
e.printStackTrace (); vLC&C-f
} zzx4;C",u
[NFAdE
~/.&Z`ls
return n; 0FW=8hFp,
} JBg>E3*N
[[|;Wr}2
=o-qu^T^u
} C1nQZtF R
zZ wD)p?_g
Iq52rI}
/* )a6i8b3
**SiteInfoBean.java |On6?5((e
*/ mPh;
package NetFox; eQeNlCG
fU8;CZnx
m|y]j4
public class SiteInfoBean { *X>rvAd3
[v&_MQ
*%8us~w5/
private String sSiteURL; //Site's URL iVl"H@m/
private String sFilePath; //Saved File's Path K~E]Fkw!;
private String sFileName; //Saved File's Name Ue\&
private int nSplitter; //Count of Splited Downloading File 2V0R|YUt
f[v??^
jc?Hip'
public SiteInfoBean() 4 I~,B[|
{//nSplitter的缺省值为5 f9rToH
//default value of nSplitter is 5 ywdNwNJ
this("","","",5); B\mdOTLQ
} p$=3&qR 6
FStfGN
+Q '|->#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L%<1C\k
{ i a|F
sSiteURL= sURL; urN&."c
sFilePath = sPath; 2<O hO ^
sFileName = sName; ?+!KucTF
this.nSplitter = nSpiltter; W)"q9(T?%
_]4cY%s
vxm`[s|QC
} Du{]r[[C
N;w1f"V}
#A/jGv^
public String getSSiteURL() ~<eiWDf
{ 3! +5MsR+
return sSiteURL; (5I]umtge
} m1<B6*iG"
f(C0&"4e
h>n;A>k@N
public void setSSiteURL(String value) }Yt0VtLt
{ v3/cNd3
sSiteURL = value; QO k%Q$^G
} B;@yOm=
RDZq(rKc
m ;KP
public String getSFilePath() a2i
{ j4l7Tx
return sFilePath; }cP3i
} +j<Nu)0iY
7OZs~6(
^NCH)zK]v
public void setSFilePath(String value) `K@
{ eGE,zkj FY
sFilePath = value; ?e@Ff"Y@e
} FHD6@{{Gp"
'Hg(N?1"
}l/md/C0
public String getSFileName() KW09qar
{ 5GY%ZRHh
return sFileName; hZFbiGQr\
} !pN,,H6Y
X3"V1@-i4$
mA4v 4z
public void setSFileName(String value) 4j | vzyc
{ lDH0bBmd0
sFileName = value; h!Ka\By8#
} ve.4""\a
+F/'+
wF%XM_M
public int getNSplitter() *yf+5q4t
{ kY|_wDBSb\
return nSplitter; p$ko=fo-*_
} S:5Nh^K
$+mmqc8
~E!"YkIr
public void setNSplitter(int nCount) )rXP2Z
{ kxdLJ_
nSplitter = nCount; Ve=0_GR0
} 4@bL` L)
} p5bH-km6
YF;8il{p
Ri,UHI4 W
/* CEUR-LK0
**Utility.java W w8[d
*/ N( /PJJ~
package NetFox; !Khsx
Pc$<Cv|vz
=HSE
public class Utility { LHacHv
A$oYw(m#
+(<CE#bb[
public Utility() :+;F"_
{ |e9}G,1
h?TE$&CL?
YZoudX'"
} KavRW.w
3QF!fll^
//线程睡眠 q/Gy&8 K
public static void sleep(int nSecond) [<%yUy
{ u54+oh|,M
try{ $;@s
Thread.sleep(nSecond); l"MEX/
} K=~h1qV:
catch(Exception e) w,l1&=d
{ "'PDreS
e.printStackTrace (); xLGAP-mx]
} P#yS]F/
} G U!XD!!&
+J^}"dG
//日志 }FFW,x
public static void log(String sMsg) KN%Xp/lkX
{ Q0r_+0[7j
System.err.println(sMsg); <}UqtDF 0
} NZD X93
W0?yPP=.
J%}}(G~
public static void log(int sMsg) {o]OxqE@
{ 2{ptV\f]D
System.err.println(sMsg); 51rM6 BT
} `*~:nvU
} G?[#<W@+
ufm#H#n)#X
;%%=G;b9
/* 8RocObY_W
**TestMethod.java !|`YNsR
*/ =GLsoc-b
package NetFox; @P~u k
e0hT
mG2}JWA
public class TestMethod { +)V6"XY-(
lID5mg31
\"f}Fx
public TestMethod() ."h;H^5
{ ///xx/weblogic60b2_win.exe B[Tw0rQ
try{ 0.Iw/e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;/YSQt)rc>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Jw86P=
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2x`# f0[
fileFetch.start(); m=n V$H
} 1dKLNE
catch(Exception e){e.printStackTrace ();} 7g=Ze~aq
J"SAA0)@
}b0qrr
} %fxGdzu7.
3kJAaI8
R!,RZ?|v
public static void main(String[] args) ,>Yz1P)L
{ ah}aL7dgO
new TestMethod(); ^beW*O!
} xxedezNko
} kDm=Cjxv
点击下载更多相关资料