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)); Zx|VOl,;
} ou\~^
for(int i=0;i<nEndPos.length-1;i++) X<:Zx#J?i
{ B5qlU4km&
nEndPos = nStartPos[i+1]; XAUHF-"WE
} %hA0
nEndPos[nEndPos.length-1] = nFileLength; 'DB'lP
} hhJ>>G4R2
} rVb61$
\~:_h#bW
q!) nSD
//启动子线程 K^[Dz\ov5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7;ddzxR4
for(int i=0;i<nStartPos.length;i++) _^NL{R/
{ <)$JA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8sU}[HH*1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 26-K:"
nStartPos,nEndPos,i); 0PJ7o#}_{@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M~*o =t
fileSplitterFetch.start(); *qw//W
} NU%W9jQYS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4nD U-P#f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;<s0~B#9}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cG4$)q;q
nEndPos = " + nFileLength); C<q@C!A
// fileSplitterFetch[nPos.length-1].start(); Z:<6Ck
MMyJAGh ^G
Si=u=FI1e
//等待子线程结束 i/q1>
//int count = 0; hR~~k~84
//是否结束while循环 e-YMFJtoK}
boolean breakWhile = false; .Za)S5U
3/RNStd<L!
, n47.S
while(!bStop) kSU]~x
{ ck#MpQ!An
write_nPos(); ??? ;H
Utility.sleep(500); !^(?C@TQ
breakWhile = true; eW;0{P
q,2 +\i
wT^QO^.
for(int i=0;i<nStartPos.length;i++) kPFqsq
{ \WZ]'o6
if(!fileSplitterFetch.bDownOver) 76RFu@k
{ qBcwM=R3P
breakWhile = false; Et+WLQ6)
break; ])$Rw$`w
} ^Z:qlYZ
} Zf8_ko;|:-
if(breakWhile) 61&A`
break; l5CFm8%
_Rm1-,3
okQ<_1e{
//count++; 05/'qf7P,U
//if(count>4) ^mCKRWOP'
// siteStop(); Gq9pJ
} VL| q`n
}ujl2uhM
Eh/Z4pzT
System.err.println("文件下载结束！"); )~H&YINhn
} p2uZ*sY(D
catch(Exception e){e.printStackTrace ();} nypG
} 5BB:.
&u~#bDh
y#)ad\
//获得文件长度 oS Apa
public long getFileSize() pF}WMt
{ wJu,N(U
int nFileLength = -1; {~+o+LV
try{ Q,<V)
URL url = new URL(siteInfoBean.getSSiteURL()); NX9K%J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o=y0=,:a?9
httpConnection.setRequestProperty("User-Agent","NetFox"); yZw5?{g@
Z@QJ5F1y
t p<wMrq<
int responseCode=httpConnection.getResponseCode(); ^%jk.*
if(responseCode>=400) ;{f4E)t 7
{ fH*1.0f]6
processErrorCode(responseCode); xfADks2w
return -2; //-2 represent access is error #jd&f,Tt
} t @vb3
,AEaW
?Oyps7hXx
String sHeader; M sQ>eSk
~3,k8C"pRq
1?,1EYT"
for(int i=1;;i++) Hh{pp ^
{ 8D6rShx =
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); t)4AQ
//Utility.log(in.readLine()); &^1{x`Qo=
sHeader=httpConnection.getHeaderFieldKey(i); {?hpW+1,#
if(sHeader!=null) ?:+sjHzXT
{ 9U]j@*QN
if(sHeader.equals("Content-Length")) G7uYkJO
{ A8U\/GP
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); hG8<@
break; pUD(5v*0R
} $ n"*scyI
} M~,N~ N1
else Td,s"p>Vq
break; :hFKmoy#
} j`:D BO&)\
} l _gJC.
catch(IOException e){e.printStackTrace ();} J1g+H2
catch(Exception e){e.printStackTrace ();} 8"yZS)09
+sFpIiJg
,jq:%Y[KZ
Utility.log(nFileLength); !yo@i_1D
$L"h|>b\o
"X,*VQl:
return nFileLength; NE4 }!I
} IaT\ymm`
uZe"M(3r$
P"%f8C~r
//保存下载信息（文件指针位置） M2pFXU?]
private void write_nPos() Z]08gH
{ 9:,ZG4s
try{ \-8S"
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5jAS1XG
output.writeInt(nStartPos.length); ,{X}C
for(int i=0;i<nStartPos.length;i++) "/nbcQ*s*E
{ i"d&U7Q
// output.writeLong(nPos); r1[c+Hy
output.writeLong(fileSplitterFetch.nStartPos); IxaF*4JG
output.writeLong(fileSplitterFetch.nEndPos); BlfadM;
} (\UpJlW
output.close(); 6u>]-K5
} aM+Am,n`@
catch(IOException e){e.printStackTrace ();} >!Dp'6
catch(Exception e){e.printStackTrace ();} PUmgcMt
} 1YNw=
(0E<Fz V
;zT3Fv\
//读取保存的下载信息（文件指针位置） ksf6O$
private void read_nPos() 9,[AfI
{ }0,dG4Oo=
try{ h"7~`!"~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8]D0)
int nCount = input.readInt(); +{0v@6<(02
nStartPos = new long[nCount]; #I1q,fm
nEndPos = new long[nCount]; ?Wc+ J4
for(int i=0;i<nStartPos.length;i++) X0Wx\xDg[
{ ?j&ZzK'#^
nStartPos = input.readLong(); SY.ZEJcv
nEndPos = input.readLong(); }N&?8s=
} |DYgc$2pN
input.close(); cn: L]%<
} sI.p( -KQ
catch(IOException e){e.printStackTrace ();} YSrjg|k*
catch(Exception e){e.printStackTrace ();} IhRdn1&
} \)?+6D'#
Lt ^*L%x
3N5@<:2`
private void processErrorCode(int nErrorCode) F^Bk @
{ W-*HAS
System.err.println("Error Code : " + nErrorCode); }2Tq[rl~s
} /b\c<'3NY
$01csj
(%OZ `?`
//停止文件下载 #0PZa$kM(o
public void siteStop() *?\u5O(
{ )|_L?q#w!'
bStop = true; mFeR~Bi>!
for(int i=0;i<nStartPos.length;i++) F2Y!aR
fileSplitterFetch.splitterStop(); Ot)S\s>
M4D @G
3-&~jm~"
} uq;yR[w"
} N6v?Qzvi
//负责部分文件的抓取 li,rPUCt
**FileSplitterFetch.java r6kJV4I=re
*/ :t<S
package NetFox; [:(/cKo
Oxa8ue?
``eam8Az_U
import java.io.*; z1]nC]2
import java.net.*; QM* T?PR
f%i%QZP
Xhq6l3M
public class FileSplitterFetch extends Thread { +g kJrw
.xuzu#-
!\$V?*p7
String sURL; //File URL $wi4cHh
long nStartPos; //File Snippet Start Position o.kDOqd
long nEndPos; //File Snippet End Position T2/:C7zL
int nThreadID; //Thread's ID nmts% u
boolean bDownOver = false; //Downing is over s2<[@@@q
boolean bStop = false; //Stop identical Uqb]&2
FileAccessI fileAccessI = null; //File Access interface ~\AF\n%
d#]hqy
/Q3\6DCl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7F6B
{ @"MQ6u G>
this.sURL = sURL; s'oNW
this.nStartPos = nStart; M2N8?Ycv3
this.nEndPos = nEnd; #4b]j".P!n
nThreadID = id; KN[;z2i
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bc4V&
} C l,vBjl h
}{VOyPG
vXRY/Zzj1
public void run() jeJgDAUv
{ e).;;0
while(nStartPos < nEndPos && !bStop) |oke)w=gn
{ 4l%1D.3-O
9aY8`B
Hcwfe=K&/
try{ Zi.' V
URL url = new URL(sURL); _1&Ar4:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <JH,B91
httpConnection.setRequestProperty("User-Agent","NetFox"); *dw.Ug
String sProperty = "bytes="+nStartPos+"-"; l"%80"zO
httpConnection.setRequestProperty("RANGE",sProperty); GPK\nz}
Utility.log(sProperty); >>,G3/Zd*
$q)YC.5$
z__?kY
InputStream input = httpConnection.getInputStream(); Mh4MaLw
//logResponseHead(httpConnection); ;_)~h$1%=
Leb|YX
1QG q;6\
byte[] b = new byte[1024]; p>;@]!YWQ
int nRead; (pd$?vRy
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j*G: 8Lg
{ DJL.P6-W
nStartPos += fileAccessI.write(b,0,nRead); qrYbc~jI7
//if(nThreadID == 1) ~qrSHn}+PU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `.@sux!lu
} +h4W<YnW
JiaR*3#
#~|k EGt
Utility.log("Thread " + nThreadID + " is over!"); P,{Q k~iu
bDownOver = true; PY.K_(D
//nPos = fileAccessI.write (b,0,nRead); hOUH1m.
} 'UIFP#GtFO
catch(Exception e){e.printStackTrace ();} *G> x07S)~
} #@$80eFq
} *uhQP47B
)*;Tt @'y
vKG\8+
//打印回应的头信息 >bh+!5Y0
public void logResponseHead(HttpURLConnection con) ],pB:=
{ &sWr)>vs
for(int i=1;;i++) j)mU`b_
{ bTc>-e,
String header=con.getHeaderFieldKey(i); 9kH~=`:?
if(header!=null) 0%rDDB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fd&Fn=!
Utility.log(header+" : "+con.getHeaderField(header)); Ak9{P`
else M?eP1v:<+G
break; e$Ds2%SaT
} j8` B
} "/aZ*mkjfJ
PN l/}'
0\tac/
public void splitterStop() #&}- q RA
{ CUI3^;&S
bStop = true; m4hkV>$d
} @kFZN6
[Y .8C$0
K$,Zg
} 5wx_ol}2
JY#vq'dl|
JX=rL6Y@:;
/* 1'E=R0`pA
**FileAccess.java kg7F8($
*//文件访问(定位，写) w*VN=
package NetFox; _YF>Y=D-
import java.io.*; i-OD"5a`
c,~uurVi
yxt"vm;
public class FileAccessI implements Serializable{ ]<>cjk.ya
=6[.||9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u?Ffqt9'
RandomAccessFile oSavedFile; ?s^qWA
long nPos; )j36Y =r3
"[_j8,t`
.`OU\LA
public FileAccessI() throws IOException F}_b7|^
{ ;'n%\*+fHH
this("",0); =GX5T(P8k
} V!He2<
2LtDS?)@
U#[&(
public FileAccessI(String sName,long nPos) throws IOException .uJ J<
{ ,<Q
oSavedFile = new RandomAccessFile(sName,"rw"); pWV_KS
this.nPos = nPos; d?*]/ZiR
oSavedFile.seek(nPos); PlkZ)S7C
} loVg{N:
Fc5.?X-
X,k^p[Rcu
public synchronized int write(byte[] b,int nStart,int nLen) $gUlM+sK
{ N#T'}>ty
int n = -1; ^jMrM.GY
try{ + `|A/w
oSavedFile.write(b,nStart,nLen); s:3[#&PQpN
n = nLen; o9eOp3w30
} [I *_0
catch(IOException e) |(>`qL{|
{ xnZnbgO+
e.printStackTrace (); )zr*Ecz
} BiYxI{VFD
b)d;eS
>@2<^&K`
return n; zZ=SAjT QP
} [:y:_ECs6
#f2Ot<#-
L kK *.
} !Y~UO)u2
&b} \).5E
h9)S&Sk{s
/* &i5@4,p y9
**SiteInfoBean.java tMxde+$y
*/ W+ S~__K
package NetFox; bJ^h{]
`8!9Fp
<\&9Odqc
public class SiteInfoBean { TR DQ+Z
*S,~zOYN
F)^0R%{C
private String sSiteURL; //Site's URL lz,M$HG<[
private String sFilePath; //Saved File's Path xi5"?*&Sb
private String sFileName; //Saved File's Name <V&0GAZ
private int nSplitter; //Count of Splited Downloading File +{:uPY#1
U^dfNi@q
XY"b90
public SiteInfoBean() *ub2dH4/
{//nSplitter的缺省值为5 m+(Cl#+
//default value of nSplitter is 5 y:;.r:
this("","","",5); 9;@p2t*v
} %O\@rws
^&>B,;Wu
7ch9Pf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mLhM_=
{ /v 8"i^;}
sSiteURL= sURL; Q~N,QMr)k&
sFilePath = sPath; 981-[ga`Y
sFileName = sName; -<#) ]um
this.nSplitter = nSpiltter; NM3;l}Y8
5XKTb
\,#$,dUXD
} l\UjvG
mwAN9<o
}S> 4.8
public String getSSiteURL() [HILK`@@
{ FIq'W:q:
return sSiteURL; *#=Ijr~
} nR_Zrm
nfEbu4|
W==~9
public void setSSiteURL(String value) 2R/|/>T v
{ F1Z'tjj+
sSiteURL = value; LF7-??'
} *tXyd<_Hd
&6sF wK
*9'3 `^l
public String getSFilePath() @:>"VP<(
{ @]Cg5QW>T
return sFilePath; u$T]A8e
} U=n7RPw
<,} h8;Fr
xC`!uPk/pL
public void setSFilePath(String value) {-Y;!
{ :iE b^F}
sFilePath = value; eCGr_@1
} 6K.2VY#
Q#eMwM#~
T[\1=h]
public String getSFileName() HI8mNX3 "j
{ '`jGr+K,wU
return sFileName; Z[?n{vD7
} -XBZ1q
!5ps,+o
Os9SfL
public void setSFileName(String value) /QXUD.( 8
{ 3xyrWl
sFileName = value; <h#*wy:o2
} 5u$.!l8Nl
g>/Y}{sL-
\|HtE(uCM1
public int getNSplitter() b| L;*<KU
{ s#X/ F
return nSplitter; J M`w6}
} xi (@\A
-xtT,^<B
Df6i*Ko|
public void setNSplitter(int nCount) OUBGbld
{ D3Q+K
nSplitter = nCount; {)" 3
} (|QJ[@?q
} ~` tuPk~l
0Ui.nz j
$TUYxf0q
/* GHv6UIe&
**Utility.java 5 ^{~xOM5
*/ *Soi
package NetFox; Tz,-~mc
`O\>vn
;<+efYmyc
public class Utility { Fd9[Pe@?`
Ud/>oaW?s
m\>gOTpA4
public Utility() 07LyB\l~
{ ~5HkDtI)
Olzw)WjG
E+L7[
} @\by`3*Q
xFu ,e
//线程睡眠 qk& F>6<9*
public static void sleep(int nSecond) {hS!IOM
{ Rpn<"LIoB:
try{ I}8e"#
Thread.sleep(nSecond); _U~R
} %vmd2}dA
catch(Exception e) Zmu
{ b**vUt\
e.printStackTrace (); Y'/6T]a
} wv\X
} !Rv ;~f/2
Gk:fw#R
//日志 NM. e4
public static void log(String sMsg) o0r&w;!
{ B!'K20"gF
System.err.println(sMsg); IyO0~Vx>
} * F!B4go
6P{bUom?
<'\Nv._2a
public static void log(int sMsg) u&~Xgq5[
{ J^+w]2`S
System.err.println(sMsg); F,_L}
} A{_CU-,
} v47' dC
".}R$W
,hzRqFg2
/* S#ryEgc]
**TestMethod.java @GQe-04W`
*/ >.wZEQ6QK
package NetFox; 3Zp<#
<#0i*PM_
+^7cS6"L
public class TestMethod { !oz{XWE
p3P8@M
P& 1$SWNyW
public TestMethod() w:zo \
{ ///xx/weblogic60b2_win.exe <K)]kf
try{ zjoo;(?D|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J6#h~fpv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2IYzc3Z{9
SiteFileFetch fileFetch = new SiteFileFetch(bean); JC'3x9_<z
fileFetch.start(); ;lmg0dtJ
} 2$JZ(qnN
catch(Exception e){e.printStackTrace ();} 19fa7E<
EZ!! V~
X;LYGJ{Xk
} 8~U ^G[!
?0~g1"Y-*K
ykQb;ZP8jh
public static void main(String[] args) ~<k>07
{ "dpjxH=xO
new TestMethod(); A f`Kg-c_(
} OP!R>|
} 99OZK
点击下载更多相关资料