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)); 6C_H0a/h&
} d^Cv9%X
for(int i=0;i<nEndPos.length-1;i++) &x.5TDB>%
{ o -x=/b
nEndPos = nStartPos[i+1]; ^6UE/4x!y
} pmUC4=&e
nEndPos[nEndPos.length-1] = nFileLength; &)Vuh=
} T~lHm
} _y[B/C,q
#cl|5jm+m#
V#&S&dn
//启动子线程 Y,KSr|vG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ){J,Z*&
for(int i=0;i<nStartPos.length;i++) uq!d8{IMu
{ Re;[S[D7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (^|vN;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I~M@v59C
nStartPos,nEndPos,i); Wh?3vZ^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T ^`R
fileSplitterFetch.start(); *kGk.a=
} @vi;P ^1!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F^DDN7AKH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); k+u L^teyS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XJ1<!tl
nEndPos = " + nFileLength); Vg`32nRN
// fileSplitterFetch[nPos.length-1].start(); yD^Q&1
c_6~zb?k+m
QlnI&o
//等待子线程结束 $=!_ !tr
//int count = 0; OLJ|gunA#
//是否结束while循环 !y;xt?
boolean breakWhile = false; vcp[$-$QGJ
KFHcHz
l !R >I7
while(!bStop) KupQtT<
{ {@67'jL
write_nPos(); PAjH*5IA
Utility.sleep(500); =.q8*7UY
breakWhile = true; Hc-68]T
3AC/;WB9
uWrvkLGN
for(int i=0;i<nStartPos.length;i++) g/z7_Aq/
{ C1(0jUz
if(!fileSplitterFetch.bDownOver) ^' b[#DG>F
{ V%w]HIhq
breakWhile = false; $@ZrGT
break; 3B ;aoejHm
} '_M"yg6d
} :&=`xAX-
if(breakWhile) VL@eR9}9K
break; $s9YU"
"xMnD(p
[G}l;
//count++; k%sh;1.
//if(count>4) uRRp8hht
// siteStop(); #7,;/rtO7
} 8CGjI?j
F@@6D0\X?
@O&;%IZMY
System.err.println("文件下载结束！"); 2u^/yl
} ;fKFmY41
catch(Exception e){e.printStackTrace ();} /: }"Zb
} ~`CWpc:
wb (quu
k9oLJ<.k
//获得文件长度 e_t""h4D
public long getFileSize() <.c#l':
{ 8s<t* pI2
int nFileLength = -1; QR{pph*zn-
try{ `Ct fe8
URL url = new URL(siteInfoBean.getSSiteURL()); ood,k{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2mPU /
httpConnection.setRequestProperty("User-Agent","NetFox"); ^yVKW5x
+FlO_=Bu
-@G,Ry-\t
int responseCode=httpConnection.getResponseCode(); S5xum_Dq
if(responseCode>=400) !:<n]-U
{ P4dhP-t
processErrorCode(responseCode); ]^DNzqu=@h
return -2; //-2 represent access is error ~&T%u.u7
} lX|d:HFtP
>_LZD4v!<
Z'4oE )
String sHeader; iz\GahK
}*M>gvPo
Yuqt=\? #
for(int i=1;;i++) 4^AdSuV
{ Qj',&b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .l ufE
//Utility.log(in.readLine()); e"ur+7
sHeader=httpConnection.getHeaderFieldKey(i); 5"I8ric
if(sHeader!=null) /.%AE|0+X
{ tU>?j1
if(sHeader.equals("Content-Length")) H.]rH,8
{ 4ai|*8.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !p|d[
break; md`"zV
} `_5{: 9N$
} gOKF%Ej31T
else #u<n .
break; 5Uha,Q9SA
} Jde@Th
} K&>+<bJ_
catch(IOException e){e.printStackTrace ();} a+ lGN
catch(Exception e){e.printStackTrace ();} _h8|shyP
%cFqD &6
O7D61~G]
Utility.log(nFileLength); ;dE'# Kb
gj-MkeI)
Dt\rMSjZ9
return nFileLength; "YePd*W
} ^OnZ9?C{R
&3%V%_
MY"8!
//保存下载信息（文件指针位置） eg Zb)pP
private void write_nPos() 4vbtB2
{ LP-_i}Kq
try{ /D&7 \3}
output = new DataOutputStream(new FileOutputStream(tmpFile)); 68-2EWq
output.writeInt(nStartPos.length); l#k&&rI5x.
for(int i=0;i<nStartPos.length;i++) 'n4$dv%q
{ X4Y!Z/b
// output.writeLong(nPos); T?V!%AqY:
output.writeLong(fileSplitterFetch.nStartPos); t}q\.
output.writeLong(fileSplitterFetch.nEndPos); AI\|8[kf0
} s2ixiv=
output.close(); c&a.<e3mL
} TIre,s)_
catch(IOException e){e.printStackTrace ();} 2u?k;"]V
catch(Exception e){e.printStackTrace ();} f15f)P
} |ww@V<'/#
1a>TJdoa
(,!G$~Sy
//读取保存的下载信息（文件指针位置） vv5 uU8
private void read_nPos() OX[pK_:`l
{ $~FnBD%|{
try{ }hyl)?*~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pGdo:L?
int nCount = input.readInt(); voJmNH
nStartPos = new long[nCount]; mx;1'!'fr
nEndPos = new long[nCount]; 7\nR'MOZ
for(int i=0;i<nStartPos.length;i++) Tq*K =^
{ t2 0Es
nStartPos = input.readLong(); $K}Y
nEndPos = input.readLong(); -N~eb^3[c
} S<bsrS*$
input.close(); ;j^C35
} vm Y*K
catch(IOException e){e.printStackTrace ();} 1NQstmd{
catch(Exception e){e.printStackTrace ();} bfl%yGkd/|
} Hm*?<o9mxC
"D1u2>(
i]M:ntB"
private void processErrorCode(int nErrorCode) 0; BX
{ X[r\ Qa
System.err.println("Error Code : " + nErrorCode); .T|1l$Jn
} i_M0P12
!H/5Ud9
bIP%xl Vp
//停止文件下载 1'Y7h;\~\
public void siteStop() mO(A'p "b
{ &h_do8R
bStop = true; eUeOyC
for(int i=0;i<nStartPos.length;i++) N^;rLrm*
fileSplitterFetch.splitterStop(); C6ry]R@
(f `zd.
aq-R#q
} ,3~[cE<4
} .qGfLvx%
//负责部分文件的抓取 gOL-b9W
**FileSplitterFetch.java Lx#CFrLQ*
*/ .R5(k'g?
package NetFox; 6h%_\I.Z[[
/_.1f|{B
Bq4^nDK
import java.io.*; ,ctm;T1H+
import java.net.*; {RPZq2Tpc
!aQQq[
X8Y)5,`s
public class FileSplitterFetch extends Thread { ZtPnHs.x
uk=f /nT
Zm+QhnY|
String sURL; //File URL iz@LS
long nStartPos; //File Snippet Start Position 4<(U/58a*
long nEndPos; //File Snippet End Position `_Fxb@"R
int nThreadID; //Thread's ID Hu-Y[~9^L:
boolean bDownOver = false; //Downing is over DL]\dD
boolean bStop = false; //Stop identical 3L1MMUACL
FileAccessI fileAccessI = null; //File Access interface ~H1ZQ[
MR`lF-|a|
5%1a!MM M
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6<qVeO&uZ
{ 9XEP:}5,
this.sURL = sURL; Oi-= Fp
this.nStartPos = nStart; A4
this.nEndPos = nEnd; cypb6Q_
nThreadID = id; S2,tv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -gK*&n~
} vn5O8sD
}$E341@
_KZ&/
public void run() ;VW->ia6
{ ;V)jC
while(nStartPos < nEndPos && !bStop) &&$,BFY4
{ TcKt
Pg\!\5
'VzYf^
try{ {#C)S&o)6
URL url = new URL(sURL); (YC{BM}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0LD$"0v/C3
httpConnection.setRequestProperty("User-Agent","NetFox"); L=#nnj-
String sProperty = "bytes="+nStartPos+"-"; Uuq*;L
httpConnection.setRequestProperty("RANGE",sProperty); On*pI37(\
Utility.log(sProperty); kX)QHNzP
Um2RLM%
_6!@>`u~
InputStream input = httpConnection.getInputStream(); v-ZTl4j$
//logResponseHead(httpConnection); -J'0qN!
Zc|V7+Yx
odsLFU(
byte[] b = new byte[1024]; ,6AnuA
int nRead; U *K6FWqiB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VAnP3:
{ >Sc/E}3
nStartPos += fileAccessI.write(b,0,nRead); "%E<%g
//if(nThreadID == 1) KbTd`AIL
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s9aa _Th
} u/ZV35z
M,we9];N
Q@0Zh,l
Utility.log("Thread " + nThreadID + " is over!"); -Wm'@4bH
bDownOver = true; lv!8)GX|
//nPos = fileAccessI.write (b,0,nRead); 3)0z(30
} gUWW}*\ U
catch(Exception e){e.printStackTrace ();} E -+t[W
} T:=ST3#m
} =;A>1g$
G5,g$yNs
?ytY8`PC
//打印回应的头信息 a>8&B
public void logResponseHead(HttpURLConnection con) 6QM$aLLP?
{ dng^#|X)?
for(int i=1;;i++) R>T9 H0
{ CAa&,ZR
String header=con.getHeaderFieldKey(i); PP&9ORG
if(header!=null) f~t5[D(\Q,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); me ,lE-
Utility.log(header+" : "+con.getHeaderField(header)); KEfwsNSc%
else pG(Fw>
break; OuMj%I
} dC(5I{I|
} =)YDjd_=z
FaQz03N\
V:<Z
public void splitterStop() >QSlH]M
{ >1 %|T
bStop = true; 7xh91EU:4
} U%r|hn3
!%Bhg?
u2 t=*<X
} RaC8Sq7hW
*4OB 88$
8T5W6Zs1
/* 76(/(v.x
**FileAccess.java !x[].Urj
*//文件访问(定位，写) Pe/8=+qO
package NetFox; 6lob&+
import java.io.*; ?M BOd9
AwtiV-w
)<(3 .M
public class FileAccessI implements Serializable{ p)Fi{%bc
J;*2[o.N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Mb:>
RandomAccessFile oSavedFile; YkF52_^_
long nPos; sv)4e)1
8DkZ@}
o3cE.YUF
public FileAccessI() throws IOException PS$g*x
{ tSVU,m
this("",0); .2V?G]u
} ok1-`c P
e(H{C
>udu~
public FileAccessI(String sName,long nPos) throws IOException 7G=Q9^J.H
{ ijACfl{!:t
oSavedFile = new RandomAccessFile(sName,"rw"); +:3s f%0
this.nPos = nPos; N{#9gr3zi
oSavedFile.seek(nPos); yA~1$sA1
} d]vom@iI
y<kg;-& 8
s1bb2R
public synchronized int write(byte[] b,int nStart,int nLen) uaqV)H
{ i hcSSUm
int n = -1; nm,(Wdr
try{ &mkL4jXG
oSavedFile.write(b,nStart,nLen); ,wZq~;2
n = nLen; a[jNT$8
} *nB-] w/
catch(IOException e) "#P#;]\`
{ #'4Psz
e.printStackTrace (); !.{"Ttn;s
} 7QdboEa
_'Rg7zHTp-
-ND1+`yD
return n; !@>q^_Gez
} cq~~a(IS
2oo\SmO]
J\hqK*/8
} Ze?n Q-
4mvnFY}
#<d'=R[AK
/* \Nj#1G
**SiteInfoBean.java L),r\#Y(v
*/ {__NVv
package NetFox; @$1jp4c
G^:?)WRG
afE8Kqa:H
public class SiteInfoBean { 7LsVlT[
"dHo6CT,y_
]F3fO5Z
private String sSiteURL; //Site's URL %awr3h>$
private String sFilePath; //Saved File's Path 5[]Yxl
private String sFileName; //Saved File's Name 5!BW!-q
private int nSplitter; //Count of Splited Downloading File HV{W7)
0:$pJtx"
O~|Y#T
public SiteInfoBean() :xk+`` T
{//nSplitter的缺省值为5 r-No\u_
//default value of nSplitter is 5 piFZu/~Gq\
this("","","",5); 8WpZ"
} @w(X}q1
Z+_xX
Y+eDE:4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |3g'~E?$
{ %$N,6}n
sSiteURL= sURL; <Qt9MO`a
sFilePath = sPath; \46*4?pP
sFileName = sName; cNMDI
this.nSplitter = nSpiltter; HMhdK
:Sn4Pg `Q
OVGB7CB]S
} .:O($9^Ho
:r7!HG_
!Y 9V1oVf"
public String getSSiteURL() 7bQST0?
{ Ymf@r?F<
return sSiteURL; K5F;/KR"
} ^ywDa^;-
uSv]1m_-]
H.[nr:
public void setSSiteURL(String value) [x'D+!
{ _k#GjAPM
sSiteURL = value; GK[Hs1/
} JvkTfTE7
#'n.az=1
M\RHFTB<C
public String getSFilePath() hFnUw26P
{ )Myx(w"S
return sFilePath; yd[4l%G(zS
} |uI~}pSG
@}pcj2K#
_na/&J6
public void setSFilePath(String value) |l@z7R+4*
{ WM7LCP
sFilePath = value; *JAC+<~d
} GI>(S
[=cYsW%WG
g_rk_4]
public String getSFileName() u>=\.d<
{ @>&b&uj7T
return sFileName; +U4';[LG1C
} E{}J-_oS45
d[Zx [=h
!?lvmq
public void setSFileName(String value) c}s#!|E0v
{ Wiw~oXo
sFileName = value; BAi`{?z$<
} S(/^_Y
'}:(y$9.`
a^_W}gzzd
public int getNSplitter() >vf-,B
{ (EjlnG}5l
return nSplitter; FjMKb
} ^XG$?2<U
9_8\xLk
) I(9qt>Y
public void setNSplitter(int nCount) gyegdky3
{ }R%*J
nSplitter = nCount; nM *}VI
} 'Ydr_Ses
} #m;o)KkH$r
+3sbpl2}
7]ySj<1
/* N1$PW~)Y
**Utility.java `jyyRwSoe
*/ P1)87P
package NetFox; O*Y?: t
].2t7{64
:4\%a4{Ie
public class Utility { k7j[tB#
CD5% iFy
My Ky*wD
public Utility() 6uKP BL@,
{ ; 6PRi/@
BoOuN94
u~>G8y)k9O
} gXU(0(Gq
|Y?<58[!)
//线程睡眠 q8n@fi6
public static void sleep(int nSecond) y#8 W1%{x
{ i`W~-J
try{ U| ?68B3
Thread.sleep(nSecond); mU"Am0Bdjq
} Y[_|sIy*
catch(Exception e) 'X6Z:dZY
{ _1mpsY<k
e.printStackTrace (); X|G[Ma?
} 2-jXj9kp`
} f~/hsp~Hp
7WY~v2SDF
//日志 1Kr$JIcd
public static void log(String sMsg) z30 mk
{ DuT6Od/f
System.err.println(sMsg); sv!v`zh
} ?k($Tc&Q
=F}qT|K
o!U(=:*b
public static void log(int sMsg) UFu0{rY_
{ r=SCbv
System.err.println(sMsg); q2'}S A/
} !^s -~`'\~
} N%ccy?B
d R=0K
U@CAQ?
/* ob'" ^LO\
**TestMethod.java #XB3Wden2
*/ TU58
package NetFox; gK@`0/k{
!3\$XK]5ZT
M d8(P23hS
public class TestMethod { sC.r$K+k5
`9gV8u
>B=s+}/ME
public TestMethod() {MyI3mvA
{ ///xx/weblogic60b2_win.exe IG{Me
try{ f6Lc"b3s1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #5kclu%L$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gqc6]{
SiteFileFetch fileFetch = new SiteFileFetch(bean); oylQCbT
fileFetch.start(); :zq Un&k&
} /U0Hk>$~(
catch(Exception e){e.printStackTrace ();} |)" y
^suQ7#g
+P Dk>PdEt
} RAk"C!&^m
HV-;?5
I8% -ii
public static void main(String[] args) WTM
{ Pk;yn;
new TestMethod(); 7U1M;@y
} ,4`Vl<6
} Y .cjEeL@
点击下载更多相关资料