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)); 'IQ;;[Q
} !,<rW<&;
for(int i=0;i<nEndPos.length-1;i++) \%}w7J;
{ Sc14F Fs
nEndPos = nStartPos[i+1]; 0JE*|CtK
} .k!<Oqa
nEndPos[nEndPos.length-1] = nFileLength; q~. .Z Y`7
} AB+HyZ*//
} \ lW*.<
?Gx-q+H
U+G8Hs/y
//启动子线程 %6Y\4Fe
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M#}k@ ;L3
for(int i=0;i<nStartPos.length;i++) T&ib]LmR
{ X?7s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Yij_'0vZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vyBx|TR
nStartPos,nEndPos,i); eWOZC(I*z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BD2Gv)?g
fileSplitterFetch.start(); d1}cXSQ1T
} >)t-Zh:n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "Wg5eML0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -&h<t/U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /lLG|aAe
nEndPos = " + nFileLength); Il]p >B
// fileSplitterFetch[nPos.length-1].start(); 4Q(w D
\*mKctpz]6
L-`?=- 9`
//等待子线程结束 %Y=
//int count = 0; SoHw9FtS
//是否结束while循环 a(_3271
boolean breakWhile = false; ' -td/w
k r5'E#
QfV:&b`
while(!bStop) byHXRA)39
{ ~? n)/i("
write_nPos(); i4<n#]1!t
Utility.sleep(500); !-Uq#Ea0/
breakWhile = true; \7WZFh%:
_b! TmS#F1
({<qs}H"
for(int i=0;i<nStartPos.length;i++) | MXRNA~
{ UYH&x:WEd
if(!fileSplitterFetch.bDownOver) wV q4DE
{ Y z],["*Q
breakWhile = false; %GigRA@no
break; $r1{Nh
} 2OwO|n
} ow9Vj$m
if(breakWhile) 0Wb3M"#9<
break; YK V"bI
yK>s]65&
>mMmc!u>G
//count++; mr+8[0
//if(count>4) ;F:Qz^=.a
// siteStop(); COL_c<\
} <3 I0$?xL
~}Z'/zCZf
/Z2 g>
System.err.println("文件下载结束！"); snVeOe#'S
} es1'z.UJ
catch(Exception e){e.printStackTrace ();} -+n?Q;
} 3J[ 5^
Uc0Sb
]GiDfYs7%
//获得文件长度 o(YF`;OhvS
public long getFileSize() Lf+3nN
{ CTZ#QiNP
int nFileLength = -1; to#T+d.(v
try{ x8Nij:K#
URL url = new URL(siteInfoBean.getSSiteURL()); ]g]~!":
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %(~8a
httpConnection.setRequestProperty("User-Agent","NetFox"); A}CpyRVCn
U=N]XwjVK<
sDS0cc6e
int responseCode=httpConnection.getResponseCode(); L{u1_
if(responseCode>=400) $+n5l@W
{ p><DA fB
processErrorCode(responseCode); `l-R?C?*!
return -2; //-2 represent access is error ^20x\K
} *}Gu'EU
?j$*a7[w
\l?.VE D
String sHeader; hQLh}}B
S %(R9N|
JT*Pm"}
for(int i=1;;i++) ~!ICBF~j
{ vb2aj!8_?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y#fiJ
//Utility.log(in.readLine()); wi S8S{K5
sHeader=httpConnection.getHeaderFieldKey(i); K@@Jt
if(sHeader!=null) 0hX@ta[Up
{ EakS(Q?
if(sHeader.equals("Content-Length")) oT^r
{ 9F|e.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l`vr({A
break; k6??+b:rE
} 2"B3Q:0he|
} ?v Z5 ^k
else n$jf($*
break; V2*m/JyeB
} 5YgUk[J
} F>rf cW2
catch(IOException e){e.printStackTrace ();} ]|4mD3O
catch(Exception e){e.printStackTrace ();} 6N'HXL UlQ
?`Som_vKO
J.pe&1
Utility.log(nFileLength); EhHW`
} bEu+bZ
?r}!d2:dX
return nFileLength; FUKE.Uxd
} i ,g<y
6|{uZNz
d5tpw$A
//保存下载信息（文件指针位置） W'<cAg?
private void write_nPos() ?p!+s96
{ 2O)2#N
try{ W'M\DKJ?
output = new DataOutputStream(new FileOutputStream(tmpFile)); l|K`'YS!<{
output.writeInt(nStartPos.length); ZUUfn~ORc
for(int i=0;i<nStartPos.length;i++) Y\ G^W8
{ &Qq4xn+J
// output.writeLong(nPos); p$&6E\#7
output.writeLong(fileSplitterFetch.nStartPos); P%xz"l i
output.writeLong(fileSplitterFetch.nEndPos); `-)Fx<e
} o)IcAqN$H
output.close(); vh6#Bc)i%w
} h}$]3/5H
catch(IOException e){e.printStackTrace ();} 4!tHJCq"
catch(Exception e){e.printStackTrace ();} kC2_&L
} Mq$Nra
m7~[f7U
1w|V'e?kb
//读取保存的下载信息（文件指针位置） &)|3OJ'o
private void read_nPos() [8C6%n{W
{ g@7j<UY
try{ =Pgu?WU@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @DYkWivLu
int nCount = input.readInt(); "6%vVi6
nStartPos = new long[nCount]; 4C_-MJI
nEndPos = new long[nCount]; b3!,r\9V
for(int i=0;i<nStartPos.length;i++) hX@.k|Yd
{ fO{E65uA
nStartPos = input.readLong(); B^G{k3]t
nEndPos = input.readLong(); @X6|[r&Z
} +qEvz<kch
input.close(); #]5|Qhrr+
} WS)u{ or
catch(IOException e){e.printStackTrace ();} yi/jZX
catch(Exception e){e.printStackTrace ();} yD!V;?EnK
} Q{Lsr,
IRQ3>4hI
dSBW&-p
private void processErrorCode(int nErrorCode) Ctxx.MM
{ ?OPAf4h
System.err.println("Error Code : " + nErrorCode); e/h7x\Z
} ^6 sT$set
U-EX)S^T[{
Epm=&6zf
//停止文件下载 ^R4eW|H
public void siteStop() k6 f;A
{ ,/g\;#:{@]
bStop = true; nNff~u)I
for(int i=0;i<nStartPos.length;i++) _"`U.!3*
fileSplitterFetch.splitterStop(); v#`Wf}G
xbA% 'p
o s HE4x
} /Iu._2
} jq&$YmWp
//负责部分文件的抓取 =}~hbPJM
**FileSplitterFetch.java kM?p>V6
*/ S,,3h0$X
package NetFox; RKP->@Gs
8_tMiIE-pS
+xlxhF
import java.io.*; ~4iIG}Y<
import java.net.*; `$\Y,9E}x
@.X}S"yr
$|YIr7?R
public class FileSplitterFetch extends Thread { c#e_Fs
Q(KLx)
0fPqO2
String sURL; //File URL 5i$~1ZC
long nStartPos; //File Snippet Start Position 41TB
long nEndPos; //File Snippet End Position 9c=_p'G3Fw
int nThreadID; //Thread's ID K/u`Wz~A
boolean bDownOver = false; //Downing is over WLWE%bDP
boolean bStop = false; //Stop identical ?WX&,ew~
FileAccessI fileAccessI = null; //File Access interface Cs %-f"
BKm$H!u
EhybaRy;C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?fEX&t,'
{ 2eu`X2IBcT
this.sURL = sURL; ${ ~UA6
this.nStartPos = nStart; 8E Y<^:
this.nEndPos = nEnd; 5b[:B~J
nThreadID = id; \6Ze H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O.E
} 1h+!<c q
GfU+'k;9
8P!dk5,,O
public void run() Sh]x`3 ).
{ @"HR"@pX
while(nStartPos < nEndPos && !bStop) @:xO5L}Io
{ D.<CkDB
zHB{I(q
>{4pEy
try{ zux+ooU
URL url = new URL(sURL); j78xMGKO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GD'C^\EaZ
httpConnection.setRequestProperty("User-Agent","NetFox"); .VmI4V?}h
String sProperty = "bytes="+nStartPos+"-"; Q[p0bD:
httpConnection.setRequestProperty("RANGE",sProperty); Md {,@ G
Utility.log(sProperty); )B*?se]LJ
+c\s%Gzrh
vd /_`l.D
InputStream input = httpConnection.getInputStream(); KW&&AuPb}
//logResponseHead(httpConnection); r[Q$w>
3_T'TzQu
&bj :,$@
byte[] b = new byte[1024]; =tH+e7it
int nRead; &U xN.vl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VSZ6;&2^
{ RQ{w`>K
nStartPos += fileAccessI.write(b,0,nRead); _'H<zZo
//if(nThreadID == 1) S53%*7K.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ["Q8`vV0WO
} @\!wW-:A
0 $e;#}
/@RnCjc'
Utility.log("Thread " + nThreadID + " is over!"); uU.9*B=H9
bDownOver = true; B;;D(NH
//nPos = fileAccessI.write (b,0,nRead); L238l
} 54J<ZXCs
catch(Exception e){e.printStackTrace ();} ].dTEzL9X
} y=vH8D]%X
} 9'toj%XQ
Hs=!.tZ,
7^iF,N
//打印回应的头信息 6ddkUPTF
public void logResponseHead(HttpURLConnection con) NTL#!
{ m4Wn$Z
for(int i=1;;i++) E}@8sY L
{ f/;\/Q[Z7
String header=con.getHeaderFieldKey(i); 45MK|4\Y_
if(header!=null) t48(GKF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +H&_Z38n
Utility.log(header+" : "+con.getHeaderField(header)); iW"L!t#\|
else 1wc -v@E
break; -'PpY302
} ;@d%<yMf@
} XFu@XUk!K
4E |6l
;7`<.y
public void splitterStop() g=Qga09
{ -Ez|
bStop = true; f6L_uk`{
} zW0AB8l
&vMH AZd
INbjk;k
} m]-8?B1`Y
Y6L+3*Qt
lIFt/
/* kmc9P&
**FileAccess.java u=E?N:I~F
*//文件访问(定位，写) '-i tn
package NetFox; h{* O9O<
import java.io.*; p fBO5Ys
_kY5 6
@eTsS%f2
public class FileAccessI implements Serializable{ ax^${s|{-
/a$+EQ$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 owMH
RandomAccessFile oSavedFile; @6j*XF
long nPos; #>v7" <
pz&=5F
jujx3rnK?
public FileAccessI() throws IOException D} .t
{ 3-mw-;.
this("",0); ,K9UT#h
} `C*!de]Y%
f<w*l<@
VNYLps@4H
public FileAccessI(String sName,long nPos) throws IOException <Y#R]gf1
{ !GIsmqVY
oSavedFile = new RandomAccessFile(sName,"rw"); HQ s)T
this.nPos = nPos; Z@[,"{Sn
oSavedFile.seek(nPos); __ mtZ{
} !%u#J:z2
YjX=@
42wcpSp
public synchronized int write(byte[] b,int nStart,int nLen) Mb>6.l
{ CD&m4^X5D
int n = -1; AltE~D/4
try{ +uLo~GdbE
oSavedFile.write(b,nStart,nLen); .d"+M{I
n = nLen; oX}n"5o:
} R{[Q+y'E
catch(IOException e) "T&uS1+=c
{ uWWv`bI>x
e.printStackTrace (); Un/fP1
} %7d"()L
n21$57`4
t<|s&
return n; .u*].As=
} 'u3+k.
y[|g!9Rp
=+"'=o
} ;yZ N "r
+E [bLz^
KB"iF}\P0
/* $0*47+f
**SiteInfoBean.java MzG ryM-
*/ &!a2%%1#N
package NetFox; lBn*G&(P
m4DH90~a8
5HbTgNI
public class SiteInfoBean { Eo Urc9G2
<!N;(nZ9}O
z}8YrVr@
private String sSiteURL; //Site's URL hX_p5a1t
private String sFilePath; //Saved File's Path A pjqSz"
private String sFileName; //Saved File's Name 7[H`;l
private int nSplitter; //Count of Splited Downloading File YxtkI:C?
{^f0RGJg9
Q*C4 q`
public SiteInfoBean() zrew:5*uZ
{//nSplitter的缺省值为5 Cv~hU%1T
//default value of nSplitter is 5 Qf|}%}%fp
this("","","",5); "?{yVu~9
} d8kwW!m+
e1loI8
S<_pGz$V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9Bk}g50$#
{ be/1-=m
sSiteURL= sURL; n`}&,UA$4
sFilePath = sPath; N 9&@,3
sFileName = sName; Mak9qaWqF>
this.nSplitter = nSpiltter; BZ<z@DJp
GzXP
]'h)7
} #5C3S3e=
O|RO j
#P-HV
public String getSSiteURL() X{xJ*T y'
{ N ]7a=
return sSiteURL; zsXH{atY
} a1`cI5n
"|'`'W
tTFoS[V
public void setSSiteURL(String value) 93Gur(j^
{ y+scJ+<
sSiteURL = value; E E|zY%
} %gMpV
i 9tJHeSm
wDhcHB
public String getSFilePath() 'h^DI`
{ $JB:rozE
return sFilePath; gyQ9Z}
} =(X'c.%i
7=.VqC^
Z{ Zox[/
public void setSFilePath(String value) G^ZkY
{ &8AS=v
sFilePath = value; >v_5xd9
} thPH_DW>eb
!;*2*WuO;
,*Z[P%<9
public String getSFileName() WJU NJN
{ *6D%mrK
return sFileName; !;aC9VhSU
} ]2Fo.n
FFeRE{,
|J Q:.h
public void setSFileName(String value) j'*p
{ x\hn;i<
sFileName = value; !J=;Z9
} WQLL[{mhS
TJ[jZuT:
gZEA;N:H%<
public int getNSplitter() DVoV:pk
{ q&$0i
return nSplitter; CotMV^
} Z)O>h^0
Eb[H3v48,
R,w54},
public void setNSplitter(int nCount) T:S{3
{ uP=_-ZUW
nSplitter = nCount; e3={$Ah
} Z^`=!n-V
} T{H#]BF<E
Vc52s+7=8
ROt0<^<
/* y]pN=<*h5
**Utility.java ?> MoV5
*/ Q xF8=p
package NetFox; `?o1cf A
l&sO?P[ /
Xf_tj:eO~
public class Utility { 5-5(`OZ{'
1xdESorX(
Y5i`pY/}#?
public Utility() G2+)R^FSC
{ D@(M+u9/%
ul=a\;3x#|
?J@?,rZQ^V
} {8Jk=)(md
<#p|z`N
//线程睡眠 -KwL9J4u
public static void sleep(int nSecond) ilRm}lU|x
{ %QsSR'`
try{ .xz,pn}
Thread.sleep(nSecond); X\^& nLa
} svq9@!go
catch(Exception e) M`C~6Mf+
{ #:vDBP05.m
e.printStackTrace (); qgC-@I
} v_ nBh,2
} K!D_PxV
_/]:=_bf_z
//日志 G\:psx/
public static void log(String sMsg) M*~v'L_sI
{ H8<7#
System.err.println(sMsg); :&1=8^BY
} nA_ zP4
%hQMC'c
kk/+Vx~
public static void log(int sMsg) %j[LRY/
{ YKw!pu=
System.err.println(sMsg); ZLN_,/7
} 1^60I#Vr@
} ny
3dX=xuQ%/
@1/}-.(n
/* jgo<#AJ/E
**TestMethod.java f.$aFOn
*/ ^!o1l-Y^gr
package NetFox; !7kLFW
KXx@ {cv
PQ&Q71
public class TestMethod { /_:T\`5uO
@O<@f8-
#lyM+.T
public TestMethod() A"BtVy[[9
{ ///xx/weblogic60b2_win.exe V6z@"+
try{ wHt#'`5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uzVG q!'H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1O]5/Eu
SiteFileFetch fileFetch = new SiteFileFetch(bean); f1CMR4D
fileFetch.start(); hP4)8>
} |?2 hml
catch(Exception e){e.printStackTrace ();} i!.I;@
Wlr&g xZ
h=K36a)
} e\^g|60f_
w]W`R.
[V2omSZo
public static void main(String[] args) ~E<PtDab
{ (?!(0Ywbg
new TestMethod(); qlz9&w
} ;e~{TkD
} Ere?d~8
点击下载更多相关资料