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)); :b<KX%g
} %mJ~F*Dy
for(int i=0;i<nEndPos.length-1;i++) -E}>h[;qZ
{ au,jAk
nEndPos = nStartPos[i+1]; 8H7O/n
} k)|'JDm
nEndPos[nEndPos.length-1] = nFileLength; wy YtpW
} |G)Y8 #D
} Q g$($
{v,{x1
})KJ60B
//启动子线程 bI#<Ee0nJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; di--:h/
for(int i=0;i<nStartPos.length;i++) ,TEuM|
{ ) b/n)%6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ENO? ;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b~jIv:9T
nStartPos,nEndPos,i); epn#qeX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !O 4<I_EY{
fileSplitterFetch.start(); 6zv;lx0<D&
} amMjuyW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '7t|I6$ow
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ix^gAot
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^Wif!u/HM
nEndPos = " + nFileLength); VccM=w%*
// fileSplitterFetch[nPos.length-1].start(); 6g}^Q?cpV#
&{ DR6
1;aF5~&
//等待子线程结束 ;i.I&*t
//int count = 0; l<W*/}3
//是否结束while循环 *X~B-a|nJ
boolean breakWhile = false; PEfE'lGj
F%9cS :
L{Q4=p,A
while(!bStop) pF|8OB%
{ *wViH
write_nPos(); jYrym-
Utility.sleep(500); ZH_FA
breakWhile = true; stX'yya
`0Yt1Z&
C%0<1mp
for(int i=0;i<nStartPos.length;i++) sS-W~u|C
{ /%62X{=>;
if(!fileSplitterFetch.bDownOver) a#^_"GX
{ u\M4`p!g=
breakWhile = false; kNRyOUy
break; 'G<}U343=8
} >~h>#{&
} L^3~gM"!
if(breakWhile) 3b+7^0frY#
break; PP!l
,wEM Jh
ZyHIMo|
//count++; /.7$`d
//if(count>4) ,c@r` x
// siteStop(); cT_uJbP+
} TP~( r
Hr /W6C
1a5?)D
System.err.println("文件下载结束！"); U&,r4>V@h>
} 6 M*b6
catch(Exception e){e.printStackTrace ();} >sn"
} 4xv9a;fP
?F)_T
)!N2'Ld
//获得文件长度 +xn&K"]:3
public long getFileSize() chKF6n
{ Uy(vELB
int nFileLength = -1; 6lN?)<uQ
try{ 8rGl&
URL url = new URL(siteInfoBean.getSSiteURL()); axWM|Bw<+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mG>T`c|r3
httpConnection.setRequestProperty("User-Agent","NetFox"); o,g6JTh
issT{&T
-"2<h:#
int responseCode=httpConnection.getResponseCode(); v;K{|zUdB
if(responseCode>=400) RcY6V_Qx
{ nsZDZ/jx
processErrorCode(responseCode); 8dr0 DF$c
return -2; //-2 represent access is error W3FymCI
} qRgK_/[]
D_O5k|-V
p^p'/$<6_
String sHeader; 2dv|6p
mw:3q6
)W[KD,0+j
for(int i=1;;i++) QV`X?m
{ eA~J4k_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K{, W_^
//Utility.log(in.readLine()); ^fA3<|
sHeader=httpConnection.getHeaderFieldKey(i); JOA%Y;`<#
if(sHeader!=null) }9MW!Ss
{ Z|]l"W*w
if(sHeader.equals("Content-Length")) \B*k_W/r@
{ #rh0r`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); '}wG"0
break; vs5 D:cZ}
} {KW&wsI
} 6$W-?
else :`{9x%o;
break; *raIV]W3
} fGu5%T,
} 6&i[g
catch(IOException e){e.printStackTrace ();} K~7'@\2 ?
catch(Exception e){e.printStackTrace ();} p+u{W"I`
vN{vJlpY
]+}:VaeA
Utility.log(nFileLength); VFe-#"0ZO
R=2 gtW"r
#]?,gwvTf
return nFileLength; o%kSR ]V|
} gg lNpzj
_DNkdS [[
`l HKQwu
//保存下载信息（文件指针位置） @)aXNQY
private void write_nPos() (Q}PeKM?jq
{ H=JP3ID>{
try{ ^%~Et>C
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3&.TU5]`-
output.writeInt(nStartPos.length); FiV^n6-F`
for(int i=0;i<nStartPos.length;i++) >GdLEE'w
{ 9`LU=Xv/
// output.writeLong(nPos); h#(.(d
output.writeLong(fileSplitterFetch.nStartPos); :d!i[W*
output.writeLong(fileSplitterFetch.nEndPos); tEi@p;Z>
} sW>P-
output.close(); ?TL2'U|M
} }0k"SwX
catch(IOException e){e.printStackTrace ();} "uV0Oj9:
catch(Exception e){e.printStackTrace ();} +=n x|:no
} -L^0-g
Mft0Dj/
9`nP(~
//读取保存的下载信息（文件指针位置） *X-~TC0 [
private void read_nPos() i~v@
{ [8V(N2
try{ TE*>a5C|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -~rr<D\
int nCount = input.readInt(); &5kjjQ*HB
nStartPos = new long[nCount]; <a4iL3
nEndPos = new long[nCount]; /ieu)m:2
for(int i=0;i<nStartPos.length;i++) ^L*VW gi9
{ 3L 1lq .
nStartPos = input.readLong(); ~2, wI<Nz
nEndPos = input.readLong(); Og&0Z)%
} SdEb[
input.close(); L<[,7V
} [)b/uR
catch(IOException e){e.printStackTrace ();} [T$$od[.
catch(Exception e){e.printStackTrace ();} o m{n"cg
} 0ER6cTo-t
7|{%CckN
ByB0>G''.
private void processErrorCode(int nErrorCode) mCEKEX
{ T }8r;<P6
System.err.println("Error Code : " + nErrorCode); p ] $
} N#2nH1C
PBPJ/puW
#b]}cwd!
//停止文件下载 ;6\Ski0=l
public void siteStop() ;GSfN
{ :5q*46n
bStop = true; @; j0c_^"!
for(int i=0;i<nStartPos.length;i++) zm_hLk
fileSplitterFetch.splitterStop(); g,z&{pZch
gZ79u
~gzpX,{n
} hj#+8=
} H)?" 8 s
//负责部分文件的抓取 ]0/~6f
**FileSplitterFetch.java 34O+#0<y~
*/ f|[5&,2<
package NetFox; JydQA_
.{Eg(1At
}E)8soQR
import java.io.*; x""Mxn]gD
import java.net.*; ZQ-z2s9U
HzO0K=Z=R0
q4IjCu+
public class FileSplitterFetch extends Thread { )}zA,FOA*
Qbe{/
o^.s!C%j
String sURL; //File URL 8Vg`;_-
long nStartPos; //File Snippet Start Position JOE{&^j
long nEndPos; //File Snippet End Position `P)64So-1
int nThreadID; //Thread's ID 5qODS_Eq
boolean bDownOver = false; //Downing is over &55uT;7] a
boolean bStop = false; //Stop identical |[n|=ORI'
FileAccessI fileAccessI = null; //File Access interface A.'`FtV
Y9(i}uTi
E%v[7 ST
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5kL#V
{ C*6bR? I9
this.sURL = sURL; }M"'K2_Z
this.nStartPos = nStart; (}7o a9Q<
this.nEndPos = nEnd; CBgFB-!qpe
nThreadID = id; 9#=IrlV4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TJGKQyG$L
} 14)kKWG
>Gu>T\jpe.
I^C ]6D{
public void run() =<tJAoVV
{ IEKX'+t'
while(nStartPos < nEndPos && !bStop) cB{;Nh6"
{ 4dD@lG~
p44uozbK
F@*r%[S/
try{ looPO:bo^
URL url = new URL(sURL); zw;(:fgY#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^O\1v
httpConnection.setRequestProperty("User-Agent","NetFox"); f>JzG,-
String sProperty = "bytes="+nStartPos+"-"; {&AT}7
httpConnection.setRequestProperty("RANGE",sProperty); @eD~FNf-]
Utility.log(sProperty); -T="Ml&
IU"!oM^
<P)%Ms
InputStream input = httpConnection.getInputStream(); LAjw!QB
//logResponseHead(httpConnection); tYxlM!
B 0fo[Ev
Y&Nv>o_}5
byte[] b = new byte[1024]; hFF&(t2{^
int nRead; '{_tDboY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bsS|!KT
{ JL*]9$o
nStartPos += fileAccessI.write(b,0,nRead); er}'}n`@q
//if(nThreadID == 1) ^|axtVhMO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _rWXcK3cjr
} SodW5v a
GTX&:5H\t
cyn]>1ZM
Utility.log("Thread " + nThreadID + " is over!"); #B{F{,vlu,
bDownOver = true; <L[)P{jn?p
//nPos = fileAccessI.write (b,0,nRead); 2Uw}'J_N
} :=KGQ3V~eK
catch(Exception e){e.printStackTrace ();} -cS4B//IK8
} J!qEj{
} ]?5@ObG
&]A1 _dy
HAOrwJFqU
//打印回应的头信息 )"Yah
public void logResponseHead(HttpURLConnection con) 8IcQpn#
{ Xrs~ove1V
for(int i=1;;i++) A.*nDl`H
{ 7 @Qlp$[F
String header=con.getHeaderFieldKey(i); 81 Not
if(header!=null) iONql7S @
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {nWtNyJpS
Utility.log(header+" : "+con.getHeaderField(header)); =<tEc+!T3
else ;(Va_
break; ",oUVl
} t$Ji{t-
} }Qu 7o
~|jy$*m4A
:D7!6}%
public void splitterStop() JVYYwA^.
{ DdW8~yI&
bStop = true; &cejy>K
} BNUf0;
JVCgYY({KQ
/R?uxhV
} >}tG^)os
PhdL@Mr
MH(g<4>*
/* clV/i&]Qa
**FileAccess.java 3 +9|7=d
*//文件访问(定位，写) TUCpmj
package NetFox; l$@lk?dc
import java.io.*; Y)5}bmL
7hE=+V8
kKO]q#9sO
public class FileAccessI implements Serializable{ ?NeB_<dLa`
@K>Pw arl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;f*xOdi*k
RandomAccessFile oSavedFile; Jx7^|A
long nPos; jl7-"V>j?;
8`<GplO
9&jNdB
public FileAccessI() throws IOException -I<`!kH*
{ 6ng9 o6
this("",0); M6n.uho/
} )f|6=x4
z81!F'x;
A}O9e
public FileAccessI(String sName,long nPos) throws IOException (CwaOm{g
{ Cl=ExpX/O
oSavedFile = new RandomAccessFile(sName,"rw"); o^J&c_U\3'
this.nPos = nPos; 4(]('[M
oSavedFile.seek(nPos); 3iwZUqyq
} v-@@>?W-
M1\/ueOe
->UrWW^
public synchronized int write(byte[] b,int nStart,int nLen) AG%aH=TKp
{ J(GLPCO$K
int n = -1; ponvi42u
try{ (d\bSo$]
oSavedFile.write(b,nStart,nLen); ;anG F0x
n = nLen; ,@MPzpH
} %hh8\5l.:
catch(IOException e) (6b%;2k
{ GW#Wy=(_
e.printStackTrace (); L x&ZWF$
} 2sH5<5G'
.`9KB3
Mf"B!WU>]B
return n; R8)"M(u=l
} ;o=mL_[
#(G&%I A|;
-W,b*U
} J!>oC_0]8
h !1c(UR
ycN_<
/* 3lqhjA
**SiteInfoBean.java <R$|J|
*/ >F v8 -
package NetFox; AseY.0
!ywc).]e
&3efJ?8
public class SiteInfoBean { 7Fx8&Z
#,Y}
r`@Dgo}
private String sSiteURL; //Site's URL IYFA>*Es
private String sFilePath; //Saved File's Path FdD'Hp+
private String sFileName; //Saved File's Name |9h[Q[m
private int nSplitter; //Count of Splited Downloading File ~Q0}>m,S
`N0E;=g
~czt=
public SiteInfoBean() DDEn63{
{//nSplitter的缺省值为5 [iD!!{6+
//default value of nSplitter is 5 jn'8F$GU
this("","","",5); z&8#1'
} ?.H*!u+9>
slbV[xR
~F-,Q_|-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >JhQ=j
{ 6{6tg>|L)
sSiteURL= sURL; %F7k| Na
sFilePath = sPath; Yp8$0KK
sFileName = sName; IM+PjYJ
this.nSplitter = nSpiltter; R!=XMV3$PH
.6*A~%-=[d
BeRn9[
} ~H.;pJ{ 8
\a#2Wm
%AFy{l
public String getSSiteURL() R?(j#bk
{ GUxhCoxb
return sSiteURL; 6ZE]7~X
} N78Ev7PN
)L?Tq"hy
Z=xrjE
public void setSSiteURL(String value) bF.Aj8ZQ
{ qr*/}F6
sSiteURL = value; '#fj)
} :MpCj<<[
?$?Ni)Z
4d#W[
public String getSFilePath() "](~VF[J8
{ XxGm,A+>Ty
return sFilePath; bFpwq#PDW>
} rr*IIG&.5
E4{8 $:q=
\,WPFV
public void setSFilePath(String value) c~V\,lcI
{ ??F{Gli"C`
sFilePath = value; #KIHq2:.4
} `c icjA@~
B\6\QQ;rUo
hE;
public String getSFileName() pJmn;XbME
{ \%)p7PNY
return sFileName; ojaZC,}
} B\Uj
{MHr]A}X\
@M1U)JoQ
public void setSFileName(String value) f-Sb:O!V
{ 5b&'gd^d
sFileName = value; 30<^0J.1
} bV"0}|A~K
:KQ<rLd
g {00i
public int getNSplitter() ;y"DEFs,u
{ ykZ)`E]P`
return nSplitter; <v\|@@X
} *StJ5c_kg2
U@9n7F
6 R!0v8
public void setNSplitter(int nCount) uB%`Bx'OW
{ # RtrHm
nSplitter = nCount; G B15
} j9Lc2'
} n7S[ F3
J~==<?j:
[P^ .=F
/* aJub("
**Utility.java xHf l>C'
*/ noacnQ_I$
package NetFox; YcIk{_N3
4u<oe_n
E]68IuP@'
public class Utility { s>kzt1,x
v8LKv`I's
x{=ty*E
public Utility() +;vfn>^!b
{ /V,:gLpQ
8 }-"&-X
WKN\*N<
} spJB6n(
;lP)
//线程睡眠 1:8ZS
public static void sleep(int nSecond) "]sr4Jg=
{ zgLm~
try{ P5[.2y_qM
Thread.sleep(nSecond); >]Y`-*vw&
} 5RqkAC
catch(Exception e) V97Eb>@
{ |W?x6]~.R
e.printStackTrace (); I&4|T<j
} mp}ZHufG
} "BK&C6]
t/HE@xPxI5
//日志 )jnxR${M
public static void log(String sMsg) Oq[tgmf
{ CYz]tv}g:
System.err.println(sMsg); 4/$]wK`
} 3^8%/5$v
CT/`Kg_
`a] /e
public static void log(int sMsg) Zd042 %
{ MwiT1sB~
System.err.println(sMsg); #*5A]"k
} n:HF&j4C,
} gQ&FO~cr
p!173y,nL
[$B
/* !}U&%2<69
**TestMethod.java Fe8xOo6
*/ 3rs=EMz:w
package NetFox; >*EcX3
-v`;^X
Bisht%]^
public class TestMethod { wF}/7b54
y;uk|#qnPS
w_6h $"^x
public TestMethod() gzxLHPiw
{ ///xx/weblogic60b2_win.exe LvB-%@n
try{ /,wG$b+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y*J,9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,myl9s
SiteFileFetch fileFetch = new SiteFileFetch(bean); EFhe``
fileFetch.start(); 7R ;!
} Wo\NX05-?
catch(Exception e){e.printStackTrace ();} (C1]R41'
D[ny%9 :
"J$vt`
} wtaeF+u-R-
8MV=?
'xhX\?mD
public static void main(String[] args) 4k}u`8 a
{ m;k' j@:
new TestMethod(); UfXqcyY(
} [/6IEt3}B
} nx84l7<
点击下载更多相关资料