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)); .c03}RTC^
} Q~b_dx{m
for(int i=0;i<nEndPos.length-1;i++) l:x_j\
{ rX:1_q`xA
nEndPos = nStartPos[i+1]; t+J)dr
} ~n8F7
nEndPos[nEndPos.length-1] = nFileLength; [m %W:Ez
} rCkYfTYI
} QY@nE
%~G0[fG
7fUi?41XA
//启动子线程 K# /Ch5?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {aT92-D3
for(int i=0;i<nStartPos.length;i++) Ae.]F)w_\
{ 0T=jR{j!o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), unpfA#&!"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FGDw;lEa9[
nStartPos,nEndPos,i); pL%4= ]m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f7S^yA[[
fileSplitterFetch.start(); c_t7RWV}
} u^!&{q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aam1tm#Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `9:v*KuM#R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O-?z' @5cI
nEndPos = " + nFileLength); o%$<LaQG5
// fileSplitterFetch[nPos.length-1].start(); n|J.)E.
[GOX0}$?
HK^a:BI
//等待子线程结束 #DrZ`Aq
//int count = 0; p?_'|#tz
//是否结束while循环 .&Y,D-h}7|
boolean breakWhile = false; G[y&`Qc)G
3LT+9ad2d
Hxj'38Y
while(!bStop) #*[,woNk
{ gD,A9a(3
write_nPos(); A>H*`{}
Utility.sleep(500); FfZ{%E
breakWhile = true; u!m,ilAnd
Z#srQD3].(
=ZFcxGo
for(int i=0;i<nStartPos.length;i++) b,=,px
{ AECxd[k$9
if(!fileSplitterFetch.bDownOver) V+P8P7y37B
{ i0i.sizu
breakWhile = false; bCH*8,Bmh
break; p)K9ZI
} ?3.(Vqwog
} 0G+L1a-
if(breakWhile) }G"r3*
break; Sn_z
';i"?D?NAk
m$j n5:
//count++; 6GvhEulYR
//if(count>4) !"Z."fm*
// siteStop(); ~e,f)?
} IwZZewb-a
qz-#LZFTR
&':UlzG
System.err.println("文件下载结束！"); /zChdjz
} t;Fbt("]:
catch(Exception e){e.printStackTrace ();} COxZ Q
} @n5;|`)\
+!mNm?H[!
7I@9v=xV
//获得文件长度 zav*
public long getFileSize() TmRrub
{ 'LtgA|c=
int nFileLength = -1; Ek gZxT_&
try{ Pu/-Qpqh
URL url = new URL(siteInfoBean.getSSiteURL()); (cPeee%Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Hsd|ka$x>
httpConnection.setRequestProperty("User-Agent","NetFox"); *l-Dh:
U*`
6qz!M
int responseCode=httpConnection.getResponseCode(); ,f-T1v"
if(responseCode>=400) #QJ4o_
{ H]T2$'U6
processErrorCode(responseCode); w>/pQ6=OFR
return -2; //-2 represent access is error Res"0Q
} e/m'a|%:
y<IZ|f
i'eYmm96Q
String sHeader; 1FXzAc(c!
=/!{<^0
[Ls2k&)0
for(int i=1;;i++) `E4!u=%
{ cLN[o8ZU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); goBKr: &]w
//Utility.log(in.readLine()); 0k]ju
sHeader=httpConnection.getHeaderFieldKey(i); $2 +$,:
if(sHeader!=null) a?xq*|?
{ q~:'R
if(sHeader.equals("Content-Length")) mPw56>
{ 8h@)9Q]d\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k:+)$[t7
break; C[87f-g
} 8g2-8pa{
} 5qeS|]^`
else `|ck5DZT5L
break; c}I8!*\
} 3ZJagJ\O
} k_|v)\4B
catch(IOException e){e.printStackTrace ();} %RT6~0z
catch(Exception e){e.printStackTrace ();} J}Z_.:JO(w
0D]Yz`n3
i"\AyKiJ
Utility.log(nFileLength); 0F0(]7g^
^?S@v1~7d
Pu\DYP:(
return nFileLength; j5VRv$P
} lWyP[>*
^6NABXL
SUnmp
//保存下载信息（文件指针位置） r1az=$
private void write_nPos() Cak/#1
{ "<n"A7e
try{ /x8C70W^
output = new DataOutputStream(new FileOutputStream(tmpFile)); b]qfcV
output.writeInt(nStartPos.length); 51;%\@=
for(int i=0;i<nStartPos.length;i++) z1@sEfk>
{ \qd)l
// output.writeLong(nPos); pil*/&pB
output.writeLong(fileSplitterFetch.nStartPos); 4Z T
output.writeLong(fileSplitterFetch.nEndPos); '14l )1g.
} j C1^>D
output.close(); 4kY{X%9
} e#eO`bT
catch(IOException e){e.printStackTrace ();} ^N}~U5
catch(Exception e){e.printStackTrace ();} <+1w'-
} q$2taG}
Y*X6lo
/wRK[i
//读取保存的下载信息（文件指针位置） bHH}x"d[x
private void read_nPos() !.GY~f<d$
{ Y;5^w=V
try{ YU\t+/b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2Lu{@*
int nCount = input.readInt(); ve]95w9J
nStartPos = new long[nCount]; xfV2/A#h
nEndPos = new long[nCount]; 1sJJ"dC.w
for(int i=0;i<nStartPos.length;i++) {Ll8@'5
{ o!dkS/u-m
nStartPos = input.readLong(); DmpJzHj|
nEndPos = input.readLong(); g$+O<a@n
} V@xnz)^t
input.close(); xupdjT%4
} eDZ3SIZ
catch(IOException e){e.printStackTrace ();} gR6T]v
catch(Exception e){e.printStackTrace ();} l|QFNW[i
} &CsBG?@Z|
kK6>>lD'
r ($t.iS
private void processErrorCode(int nErrorCode) fOfz^W
{ u=i^F|
System.err.println("Error Code : " + nErrorCode); lxJ.h&"P
} }pZnWK+
-Z&{$J
"_}D{ws1
//停止文件下载 U"G+su->e
public void siteStop() t`3T_t Y
{ Y##P9^zH1
bStop = true; pKlT.<X7
for(int i=0;i<nStartPos.length;i++) Gjh7cm>
fileSplitterFetch.splitterStop(); oRF"[G8BV
jJnBwHp
Yx/~8K_%M?
} }u)GERWO
} #gT^hl5/
//负责部分文件的抓取 U,(+rMeY0
**FileSplitterFetch.java 74OM tLL$
*/ 2|o$eq3t
package NetFox; vw 2@}#\:
_$lQK{@rY
by[(9+/z$
import java.io.*; k/Ro74f=
import java.net.*; \kO_"{7n
#ms98pw%5
Vjd =F.V+
public class FileSplitterFetch extends Thread { c?Qg:yU
KO"iauW
) O^08]Y g
String sURL; //File URL _kLoDju%
long nStartPos; //File Snippet Start Position aE$p;I
long nEndPos; //File Snippet End Position a5&j=3)|
int nThreadID; //Thread's ID g>oLc6T
boolean bDownOver = false; //Downing is over =h!m/f^x
boolean bStop = false; //Stop identical u^p[zepW\
FileAccessI fileAccessI = null; //File Access interface S"z4jpqn3
RO8Ynm2 <
Vs{sB*:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /q]@|5I
{ Or|LyQU
this.sURL = sURL; 9hzU@m
this.nStartPos = nStart; (*gpa:Sc
this.nEndPos = nEnd; &6EfybAt^_
nThreadID = id; Br??Gdd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SQk!o{
} "YZ`g}sG
:gtwvM7/B
96j2D8=w
public void run() ,#haai(
{ V [>5
while(nStartPos < nEndPos && !bStop) RwKN
{ Q+dI,5YF
R/|o?qTrj
`lzH:B
try{ `,"Jc<R7Z
URL url = new URL(sURL); 56dl;Z)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z;:-8 HPDY
httpConnection.setRequestProperty("User-Agent","NetFox"); tDkqwF),
String sProperty = "bytes="+nStartPos+"-"; `#bcoK5
httpConnection.setRequestProperty("RANGE",sProperty); WI3!?>d
Utility.log(sProperty); j>23QPG`6U
"bH ~CG:Y
q<7n5kJ~
InputStream input = httpConnection.getInputStream(); 2{N0. |5
//logResponseHead(httpConnection); 0qd`Pf
`^[ra%a
yhmW-#+^e
byte[] b = new byte[1024]; Lf9h;z>#
int nRead; ^g\%VIOD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y8T.RS0
{ 6qf`P!7d]M
nStartPos += fileAccessI.write(b,0,nRead); ER+[gT1CQ
//if(nThreadID == 1) uy~j$lrn
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v\C+G[MV7
} E{J;-+t
F\;1:y~1
<s>SnOD
Utility.log("Thread " + nThreadID + " is over!"); ;7hr8?M|
bDownOver = true; $Izk]o;X~
//nPos = fileAccessI.write (b,0,nRead); ?1sY S
} x1h!_^(QfF
catch(Exception e){e.printStackTrace ();} =JkSq J)?
} T /uu='3
} i%2K%5{)$D
!;-x]_
Pmb`05\
//打印回应的头信息 S"l&=J2dc
public void logResponseHead(HttpURLConnection con) iatQHn>(
{ JI(|sAH
for(int i=1;;i++) ,*30Q
{ H2}i .
String header=con.getHeaderFieldKey(i); f?QD##~;
if(header!=null) !Fi)-o
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {Bx\Z0+'&
Utility.log(header+" : "+con.getHeaderField(header)); hSmM OS{
else gqG"t@Y+
break; !O*n6}nPE
} #]2u!ama
} .:}\Z27-c
!=pemLvH
Zh$Z$85p
public void splitterStop() y-YYDEl
{ sQw-#f7t
bStop = true; Sk-Ti\
} E_P]f%
BKk*<WMD
tq[C"| dH
} #@G2n@Hj
}V{, kK
iVRz
/* 'J}lnt[V
**FileAccess.java bc-"If Z&
*//文件访问(定位，写) _"n4SXhq
package NetFox; |Cm}%sgR\0
import java.io.*; (@zn[Nq
TocqoYX{{
UOyP6ej
public class FileAccessI implements Serializable{ 7^1ikmYY
{|cA[#j#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Tn|reXc0e
RandomAccessFile oSavedFile; v|e>zm<
long nPos; I`|>'$E[r
Ua4} dW[w
1D$k:|pP~
public FileAccessI() throws IOException rqIt}(J
{ V+Z22
this("",0); Y:wds=lA
} pw,.*N3P
(/^&3xs9
F#hM S<
public FileAccessI(String sName,long nPos) throws IOException pP .
{ Tb[GZ,/%;
oSavedFile = new RandomAccessFile(sName,"rw"); U[ed#9l>
this.nPos = nPos; l!1bmg#]$
oSavedFile.seek(nPos); ;-3M
} W$y?~2
"H({kmR
x-"7{@lz
public synchronized int write(byte[] b,int nStart,int nLen) N4Ym[l
{ eWFlJ;=
int n = -1; Rj8l]m6U9
try{ uzS57 O%
oSavedFile.write(b,nStart,nLen); *m;L.r`5[
n = nLen; eu~;G H
} wZ\0<skU
catch(IOException e) Cs$g]&a
{ t6tqv
e.printStackTrace (); #(7OvW+y
} ]b[3 th*
}.Ug`7%G
%V$^CWOy
return n; hX^XtIC=
} W uQdz&s>
*Q)+Y&qn
$u P{,ML
} + 7Z%N9
NIgt"o[I
giPyo"SD
/* V; ChrmE
**SiteInfoBean.java :%0Z
*/ U_:/>8})d
package NetFox; R\XJ
%c&h:7);
3KqylC&.
public class SiteInfoBean { %T&kK2d;
MT3UJ6~P
rC'97`!K
private String sSiteURL; //Site's URL g}f@8;TY
private String sFilePath; //Saved File's Path ;;2s{{(R
private String sFileName; //Saved File's Name <|{=O9
private int nSplitter; //Count of Splited Downloading File P\Ka'i
Mqna0"IYx*
'rSM6j
public SiteInfoBean() F:n7yey
{//nSplitter的缺省值为5 3o1j l2n
//default value of nSplitter is 5 !$O +M#
this("","","",5); 5!wa$wY
} 1PWDK1GI8
$+Xohtt
9Gy1T3y5"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7,:QFV
{ a^,Xm(Wb}
sSiteURL= sURL; gG#M-2P
sFilePath = sPath; LEY$St
sFileName = sName; |'Jz(dv[
this.nSplitter = nSpiltter; FvRog<3X
}^=J]
(*#S%4(YX
} # TvY*D,
0Rj_l:d=
d!>PqPo
public String getSSiteURL() lLnD%*03
{ i`X/d=
return sSiteURL; 1Ztoj}!I
} .8k9yk
O5E\#*<K
u-8,9
public void setSSiteURL(String value) tYVmB:l
{ `}18A.K
sSiteURL = value; t1D6#JP(a
} gx3arVa
6z~6o0s~
L9@nx7D
public String getSFilePath() B lD
{ ?xIwQd0
return sFilePath; `Os@/S
} )!3sB{H
F6yMk%
oB+drDp8U
public void setSFilePath(String value) x2l~aw#?
{ e~xN[Q\0]
sFilePath = value; *M09Y'5]
} xM[m(m
Zhf+u r
4v Ug:'DM
public String getSFileName() yH irm|o
{ a8NL
return sFileName; WSUU_^.
} n%A)#AGGc
u`g|u:(r
{ZB7,\
public void setSFileName(String value) 86oa>#opU
{ ?m0|>[j
sFileName = value; SIVzc Hm
} b0t/~]9G
Z!DGCw
).5$c0`U&
public int getNSplitter() 54v}iG
{ y$'(/iyz
return nSplitter; ApR>b%
} *{6{ZKM
xO{yr[x"L
5*C#~gd&F
public void setNSplitter(int nCount) (*F/^4p!$
{ ("?V|
nSplitter = nCount; ><^ ,
} @w?hXK=
} saY":fva
CKCot
qi!+Ceo}
/* 5NHNnDhuL
**Utility.java T@Mrbravc
*/ OF-$*
package NetFox; 0F/o
>We4F2?
D5^wT>3>
public class Utility { ,#m:U5#h
z&Cz!HrS
@p"m{
public Utility() ]2Zl\}GwY
{ s,Azcqem
H85JMPZ7
NH~\kV
} k^K>*mcJ
jnho*,X
//线程睡眠 R.^ Y'TLyc
public static void sleep(int nSecond) dg-nv]7
{ b@`h]]~:
try{ `|(S]xPHM
Thread.sleep(nSecond); MfNsor
} SJ8Ax_9{q
catch(Exception e) ~Z-o2+xA
{ "n'kv!?\
e.printStackTrace (); HtpZ5
} t>Lq "]1
} n<3qr}ZG^
RzhAXI=
//日志 wNl{,aH@
public static void log(String sMsg) -c4g;;%
{ mBN+c9n/
System.err.println(sMsg); =S#9\W&6Q
} 9?]69O
Y].,}}9k
8}C_/qeM
public static void log(int sMsg) v(=?@tF}E
{ zi%Ql|zI~
System.err.println(sMsg); 9lqH
} jzvrJ14
} OGcq]ue
bY&!d.
%>Q[j`9y
/* Nk2n&(~$
**TestMethod.java XCvL`
*/ Cg_9V4h.C
package NetFox; 4]G J+a
FJQ=611@
Uhs/F:E[A
public class TestMethod { 4Dy|YH$>S
TAB'oLNp
]}4JT
public TestMethod() HQ:Y:
{ ///xx/weblogic60b2_win.exe 4g+Dp&U
try{ =aBc.PJ^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \?tE,\Ln
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); uo9FLm
SiteFileFetch fileFetch = new SiteFileFetch(bean); X~g U$
fileFetch.start(); T_)G5a
} };Pdn7;1G:
catch(Exception e){e.printStackTrace ();} j[CXIz?c
gx9=L&=d
g286 P_a`*
} `:.a5
t#d{hEr
8Wba Hw_
public static void main(String[] args) Uz=OTM
{ \r1nMw3&
new TestMethod(); PCx:
} HjCe/J ;
} eHb@qKnf
点击下载更多相关资料