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)); $p6N|p
} Gt^d;7x]
for(int i=0;i<nEndPos.length-1;i++) y lL8+7W
{ obGWxI%a
nEndPos = nStartPos[i+1]; L$JI43HZ
} .9 kyrlm
nEndPos[nEndPos.length-1] = nFileLength; Ph)|j&]
} QrS$P09=\
} #8?^C]*{0
};SV!'9s?~
vl5){@
//启动子线程 :EB,{|m
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dB)[O9K)
for(int i=0;i<nStartPos.length;i++) %,?vyY
{ `jW4H$D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), do'ORcZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !C`20,U
nStartPos,nEndPos,i); +i)AS0?d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $%He$t
fileSplitterFetch.start(); YBylyVZ
} ^ KAG|r9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (+MC<J/i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M_&4]\PkCy
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VD;j[~/Z
nEndPos = " + nFileLength); #]zhZW4
// fileSplitterFetch[nPos.length-1].start(); W8* 2;F]
BJIQ zn3
0zV 4`y
//等待子线程结束 W78o*z[O
//int count = 0; wgZrrq/W|
//是否结束while循环 $^$ECDOTB
boolean breakWhile = false; HDj$"pS
Tk+DPp^
$c9=mjwH
while(!bStop) #WEq-0L
{ kIM C~Z
write_nPos(); 9.-47|-9C
Utility.sleep(500); ak2dn]]D
breakWhile = true; d Uz<1^L
uGCtLA+sL
F@<MT<TRf
for(int i=0;i<nStartPos.length;i++) X%`KYo%
{ Xu%d,T$G
if(!fileSplitterFetch.bDownOver) t?.\|2
{ u\5g3BH
breakWhile = false; d$Em\*C
break; B(Y.`L? %E
} 0BXs&i-TP5
} 'z](xG<
if(breakWhile) DPeVKyjU
break; msG3~@q
j0?>w{e
J0qXtr%h\
//count++; V/&o]b
//if(count>4) 8r^j P.V
// siteStop(); r#I>_Utsy
} u\w2S4c
J!<#Nc
"OJr*B
System.err.println("文件下载结束！"); _#(s2.h~J
} Y eO-gY[b
catch(Exception e){e.printStackTrace ();} j@SYXKL~
} 4tnjXP8
Z"N(=B
kxy]vH6m
//获得文件长度 id4]|jb
public long getFileSize() oVEAlBm^v
{ xXPUrv5zO
int nFileLength = -1; "cQvd(kug
try{ xH@'H?
URL url = new URL(siteInfoBean.getSSiteURL()); tx)OJY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #{~7G%GPY5
httpConnection.setRequestProperty("User-Agent","NetFox"); MC6)=0:KX
DUo0w f#D^
z.j4tc9F/5
int responseCode=httpConnection.getResponseCode(); j88=f#<
if(responseCode>=400) 3B -NYJa
{ 8E 9{ Gf
processErrorCode(responseCode); ?"u'#f_
return -2; //-2 represent access is error R(GmU4
} O&=KlnI:
FdM<;}6T
g~|y$T
String sHeader; .xo_}Vw
59~FpjJ
~}9Bn)@
for(int i=1;;i++) c-`37. J
{ r8F{A6iN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h-,?a_
//Utility.log(in.readLine()); *@~`d*d
sHeader=httpConnection.getHeaderFieldKey(i); Seg#s.
if(sHeader!=null) k!9=
{ "Ac~2<V
if(sHeader.equals("Content-Length")) i.F8
{ ]qMH=>pOsj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )*Vj3Jx
break; Tfr`?:yF
} \d ui`F"Cc
} unJiE!
else |[DV\23{G
break; wn{]#n=|l
} (< :mM
} |;~nI'0O])
catch(IOException e){e.printStackTrace ();} rI *!"PL
catch(Exception e){e.printStackTrace ();} 5'62ulwMP=
NQg'|Pt(%
Vv2{^!aZ
Utility.log(nFileLength); Fdr*xHx$P
2*Va9HP!q
a" ^#!G<+
return nFileLength; TG4^_nRl
} i'Wcf1I-=
89db5Dx
L%k67>
//保存下载信息（文件指针位置） 98h :X%
private void write_nPos() R/Tj^lM
{ cB_pyX9Z
try{ :wSJ-\'$
output = new DataOutputStream(new FileOutputStream(tmpFile)); x<Iy<v7-
output.writeInt(nStartPos.length); uvR0TIF4
for(int i=0;i<nStartPos.length;i++) gj[zka0_
{ F:M/z#:~
// output.writeLong(nPos); n$IWoIdbGN
output.writeLong(fileSplitterFetch.nStartPos); -*r[
output.writeLong(fileSplitterFetch.nEndPos); HE@-uh
} $]nVr(OZ_
output.close(); >eEnQ}Y
} kHGeCJe\{
catch(IOException e){e.printStackTrace ();} 3>H2xh3Y
catch(Exception e){e.printStackTrace ();} Tw}@+-
} j/~VP2R`
D8gQRQ
?U}sQ;c$
//读取保存的下载信息（文件指针位置） 9)jo7,VM
private void read_nPos() @>+^W&
{ ,n^TN{#
try{ YfV"_G.ad|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =jsx(3V
int nCount = input.readInt(); sE^ns\&QP=
nStartPos = new long[nCount]; =.VepX|?D
nEndPos = new long[nCount]; E1^aAlVSD
for(int i=0;i<nStartPos.length;i++) (_s;aK
{ o*?[_{xW
nStartPos = input.readLong(); }Q,(u
nEndPos = input.readLong(); P_kaIPP
} -hQ96S8
input.close(); &qNP?>C!=
} IES41y<
catch(IOException e){e.printStackTrace ();} 8y-e+
catch(Exception e){e.printStackTrace ();} *iPs4Es-
} ,:c:6Y^
6.k^m&-A
-6AOK<kfI
private void processErrorCode(int nErrorCode) UIO6|*ka
{ ^xzE^"G6
System.err.println("Error Code : " + nErrorCode); aIQrb
} H<v c\r
FAH[5VDr%
"ugX /r$_
//停止文件下载 5JO[+>
public void siteStop() xWd9%,mDNR
{ }*xC:A%aS
bStop = true; C<zx'lw!
for(int i=0;i<nStartPos.length;i++) s'R~r
fileSplitterFetch.splitterStop(); bMSD/L
8W(<q|t
w g$D@E7
} ac2}3$u
} N;e;4,_ n
//负责部分文件的抓取 rdORNlK&
**FileSplitterFetch.java s4MNVT
*/ 'hxs((['\
package NetFox; (3)C_Z
QBg}2.
Wpiv1GZ%c8
import java.io.*; HR/k{"8W4Q
import java.net.*; L#@l(8.
, LCH2r
PpX{+^z-%
public class FileSplitterFetch extends Thread { L-^# 02
Bq~AU#
\W3+VG2cA
String sURL; //File URL Yt\E/*%
long nStartPos; //File Snippet Start Position dL1~]Z y
long nEndPos; //File Snippet End Position _Ym&UY.u#
int nThreadID; //Thread's ID *O"%tp6
boolean bDownOver = false; //Downing is over !X \Sp}
boolean bStop = false; //Stop identical c@0l-R{q
FileAccessI fileAccessI = null; //File Access interface ek Y?
q$e T!'x
$K=K?BV[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $#6Fnhh}
{ /ig^7+#
this.sURL = sURL; @t{{Q1
this.nStartPos = nStart; yVbg,q'?
this.nEndPos = nEnd; @ef//G+Z"
nThreadID = id; |NphG|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T{5M1r
} 31 KDeFg
Ri^sQ<~(
nOA,x
public void run() ~$ cm9>
{ 5#9`ROT9
while(nStartPos < nEndPos && !bStop) o+)m}'T8
{ VZ9e~){xA
(E2lv#[
ZwY`x')
try{ m? \#vw$
URL url = new URL(sURL); G#_(7X&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :epitpJ
httpConnection.setRequestProperty("User-Agent","NetFox"); e8WPV
String sProperty = "bytes="+nStartPos+"-"; +lY\r +;
httpConnection.setRequestProperty("RANGE",sProperty); I1eb31<
Utility.log(sProperty); hr/xpQW
mI_ 6f~
;ph+ZV
InputStream input = httpConnection.getInputStream(); DYy@t^sC
//logResponseHead(httpConnection); `Z;B^Y0
,d/CU
8EW`*+%=
byte[] b = new byte[1024]; B=o#LL
int nRead; MSxU>FX0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $=;bccIob
{ "9MX,}X*
nStartPos += fileAccessI.write(b,0,nRead); 7;$L&X
//if(nThreadID == 1) bUipp\[aV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HbJadOK
} 8yJk81 gY
.{-iq(3
+#i,87
Utility.log("Thread " + nThreadID + " is over!"); il`C,CD
bDownOver = true; +E""8kW- Z
//nPos = fileAccessI.write (b,0,nRead); Z(Ls#hp
} r`mzsO-'
catch(Exception e){e.printStackTrace ();} +ik N) D
} b_)QBE9
} {4V:[*3
&L[8Mju6
qZyt>SAx
//打印回应的头信息 ]%ZjD
public void logResponseHead(HttpURLConnection con) $AL|d[[T[
{ f6/\JVi)-
for(int i=1;;i++) s525`Q;
{ ;1(qGy4
String header=con.getHeaderFieldKey(i); D%5 {A=
if(header!=null) YA/H;707l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W+-f `
Utility.log(header+" : "+con.getHeaderField(header)); <try%p|f
else /ab K/8ZQ
break; E`sapk
} e2VL/>y`
} ;Kq<',u~
n=#[Mi $Y
<iY 9cV|}3
public void splitterStop() @/ovdf{
{ [3bwbfHhi
bStop = true; ~k:>Xo[|O
} =-a?oH-
y+~Aw"J}
.,iw2:
} l*V72!Mv
aV92.Z_Ku
'E4(!H,k
/* \[hrG?A
**FileAccess.java #f jX|b
*//文件访问(定位，写) 3`C3+
package NetFox; }~0{1&
import java.io.*; [;kj,j
!UPAEA
fh5^Gd~
public class FileAccessI implements Serializable{ ~A{[=v
K`AW?p^$Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^,\se9=(
RandomAccessFile oSavedFile; H"Em|LX^
long nPos; :fMM-?s]
W0C$*oe!_i
tI(t%~>^
public FileAccessI() throws IOException r%?}5"*
{ Yh!\:9@(
this("",0); ;-P:$zw9c
} M. UUA?d<'
vA $BBXX
$F==n4)
public FileAccessI(String sName,long nPos) throws IOException s13 d*
{ rH9|JEz
oSavedFile = new RandomAccessFile(sName,"rw"); {Ac3/UM/
this.nPos = nPos; h: (l+jr
oSavedFile.seek(nPos); kv`3Y0R-"
} QH56tQq
VE+p&0
ohG43&g~
public synchronized int write(byte[] b,int nStart,int nLen) iOA3x 8J
{ v+, w{~7RH
int n = -1; A_dYN?^?|
try{ Z{>Y':\?<
oSavedFile.write(b,nStart,nLen); z8MpE
n = nLen; -ZMl[;OM
} <H(AS'
catch(IOException e) # v/aI*Rl
{ b9!J}hto,
e.printStackTrace (); [+5SEr}
} l'X?S(fiV
:r[-7 [/
'"NdT7*+
return n; JZ*?1S>
} ~s^6Q#Z9|
fTnyCaB
1</t #r
} Zi'8~iEH
P<w>1 =
E9NGdp&-Ah
/* Nl>b'G96
**SiteInfoBean.java 7B>cmi
*/ pLFL6\{g
package NetFox; @;-Un/'C;7
b+fy&rk@-
>Sl:Z ,g;
public class SiteInfoBean { r_2VExk
~8qFM
7.=s1~p
private String sSiteURL; //Site's URL "B{xC}Tw
private String sFilePath; //Saved File's Path P) 0=@{(
private String sFileName; //Saved File's Name +vY`?k`
private int nSplitter; //Count of Splited Downloading File jYssz4)tp
F_ lj>;}a5
U8@*I>vA
public SiteInfoBean() v6(l#,
{//nSplitter的缺省值为5 gl4 f9Ff
//default value of nSplitter is 5 )e$-B]>7z
this("","","",5); ~<Qxw>S#
} EwJn1Mvq
; yC`5
}z%/6`7)|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TEy.zzt
{ k-p7Y@`+a
sSiteURL= sURL; VHkrPJ[
sFilePath = sPath; H5rNLfw '
sFileName = sName; +R jD\6bJb
this.nSplitter = nSpiltter; 6O?Sr,
UEb'E;
[}Yci:P_ +
} j;c^pLUP
Q14;G<l-
I.0Usa"z
public String getSSiteURL() q>h+Ke
{ Y .X-8
return sSiteURL; 3B]+]e~
} Bc`A]U
WN?`Od:y
fpC@3itI
public void setSSiteURL(String value) [IX!3I[J]
{ m(Xr5hw:6
sSiteURL = value; o".O#^3H%
} ~]s"PV:|
s~'C'B?
X_yU"U
public String getSFilePath() I>\?t4t
{ Tp.iRFFkP
return sFilePath; :re(khZq#
} (B4A$t
>LZ)<-Mk
'wHkE/83
public void setSFilePath(String value) {}2p1-(
{ k:yu2dQh
sFilePath = value; >.sN?5}y
} ?v*7!2;
4C*=8oe_
nqW:P$
public String getSFileName() im%3*bv-
{ Ol^EQLO
return sFileName; 9O_N iu0
} QE6-(/
/1@m#ZxA:
mhSsOmJ5
public void setSFileName(String value) vWga>IGM
{ LU=)\U@Q
sFileName = value; f*@:{2I.v
} Z1}zf(JU
ooxzM `
_^A NJ7
public int getNSplitter() _Pm}]Y:_
{ `^Sq>R!;
return nSplitter; pIjVJ9+j
} meWq9:z
dQ"W~ig
QAw,XZ.K^
public void setNSplitter(int nCount) lt"*y.%@b
{ Tj~#Xc
nSplitter = nCount; smS0Rk
} M)RQIl5
} Gi2Ey37]O
O/~^}8TLL
.OUE'5e p
/* )eyxAg
**Utility.java >gl<$LQ?X
*/ t9l7 % +y
package NetFox; VAzJclB
u{d`
(pg9cM]NA
public class Utility { =l9#/G#R
CT`X~y10
32/P(-
public Utility() cW%O-
{ jg/<"/E
.k(_j.v
md s\~l73
} `v er "s;
?5gpk1
//线程睡眠 EF~PM
public static void sleep(int nSecond) pdu
{ ' qVa/GJ
try{ Xqw7lj;K
Thread.sleep(nSecond); 1r4/McB
} tYa*%|!v
catch(Exception e) I-hhHm<@
{ s]>%_(5
e.printStackTrace (); TD9`SSpP
} xUoY|$fI
} Sa~C#[V
Wg&:xff
//日志 #{1fb%L{i
public static void log(String sMsg) .9QQ]fLs
{ %q^]./3p
System.err.println(sMsg); v\FD~
} SsZzYj.d
-/?<@*n
'_Oprx
public static void log(int sMsg) bq]a8tSB
{ RMXj)~4.
System.err.println(sMsg); b5R*]
} Y6a|\K|
} J_$~OEC~
bS<p dOX_
0rUf'S ?K
/* @9a=D<'>
**TestMethod.java Mr(3]EfgO
*/ e:<> Yq+
package NetFox; uUs>/+
.EwK>ro4
H'>
public class TestMethod { W aU_Z/{0
;;5i'h~?]J
\eCdGx?
public TestMethod() AJu.
{ ///xx/weblogic60b2_win.exe m6D4J=59
try{ (#qVtN`t
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kF .b)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 70eN]OY
SiteFileFetch fileFetch = new SiteFileFetch(bean); :Ib\v88WIv
fileFetch.start(); d\M !o*U
} `314.a6S
catch(Exception e){e.printStackTrace ();} ,~#hHhR_
J)o%83//
,?+yu6eLb
} `RRORzXoS
P9vROzXK
[G*mQ@G9
public static void main(String[] args) ;U&VPIX$
{ rv:O|wZ
new TestMethod(); e`^j_VnEH
} |~Iw
} AP%h!b5v
点击下载更多相关资料