http断点续传简单实现（java)

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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)); Gs,e8ri!
} ,p /{!BX
for(int i=0;i<nEndPos.length-1;i++) :H&G}T(#
{ &,=FPlTC=
nEndPos = nStartPos[i+1]; KV8<'g+2?
} \q3ui}-9
nEndPos[nEndPos.length-1] = nFileLength; t\a|Gp W
} m OE!`fd
} qVI0?B x
r;MFVj{
5pC}ZgEa<
//启动子线程 Z[ &d2'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^\kH^
for(int i=0;i<nStartPos.length;i++) WUo\jm[yr
{ T,jb%uPcE
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U]w"T{;@.)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iK+Vla`}
nStartPos,nEndPos,i); I8`$a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); + d3
fileSplitterFetch.start(); u`.)O2)xU
} ;ISe@yR;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eG8l^[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); iRlpNsN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Jj\lF*B
nEndPos = " + nFileLength); %?aq1 =B
// fileSplitterFetch[nPos.length-1].start(); UV0[S8A
;,e16^\' &
FpU8$o~r{
//等待子线程结束 b GI){0A
//int count = 0; #.[eZ[
//是否结束while循环 y1T(R#
boolean breakWhile = false; Hk@Gkx_
|FM*1Q[1
OG$v"Yf~
while(!bStop) 'P" i9j
{ +xU({/
write_nPos(); 3+s$K(%I
Utility.sleep(500); QIevps*
breakWhile = true; :$,MAQ'9
X(X[v]
;RX u}pd
for(int i=0;i<nStartPos.length;i++) #vxq|$e
{ Uc'}y!R
if(!fileSplitterFetch.bDownOver) R3l{.{3p2
{ Bf;_~1+vLG
breakWhile = false; 1' v!~*af
break; ^.\O)K {h
} jBOl:l,+
} -fmJkI
if(breakWhile) 9A} *
break; G$MEVfd"
i!e8-gVMP&
{&mHfN
//count++; 1ONkmVtL
//if(count>4) )y;7\-K0
// siteStop(); ^Y%_{
} u;-fG9xs
$*iovam>^]
,NS*`F[O
System.err.println("文件下载结束！"); ^N|8 B?Vg
} HOFxOBV
catch(Exception e){e.printStackTrace ();} W_JO~P
} ?SElJ?Z
(BeJ,K7
[i ~qVn2vT
//获得文件长度 =(D"(OsQ/
public long getFileSize() U|%}B(
{ l[ $bn!_e
int nFileLength = -1; E KV[cq
try{ 9tPRQM7
URL url = new URL(siteInfoBean.getSSiteURL()); /}m*|cG/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^zQI_ydG
httpConnection.setRequestProperty("User-Agent","NetFox"); s{yw1:
*1<kYrB
5HV+7zU5
int responseCode=httpConnection.getResponseCode(); cS9jGD92
if(responseCode>=400) diY7<u#
{ 9"]#.A^Q*
processErrorCode(responseCode); ud$-A
return -2; //-2 represent access is error Q}L?o
} O.(2
5P-t{<]tx
oIj=ba(n1
String sHeader; 7<] EH:9
A,cXN1V
}ARA K^%
for(int i=1;;i++) N8dxgh!,
{ lt&(S)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {}$7Bp
//Utility.log(in.readLine()); w>&*-}XX
sHeader=httpConnection.getHeaderFieldKey(i); 5FoZ$I
if(sHeader!=null) Z,.Hz\y1D
{ LZRg%3.E
if(sHeader.equals("Content-Length")) Y"GNJtsL"
{ 0 Uropam
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tbd=A]B-
break; (?na|yd
} |h\7Q1,1~2
} AAevN3a#nI
else V*uE83x1
break; E[]5Od5#
} MYWkEv7
} ,_Z(!| rW
catch(IOException e){e.printStackTrace ();} H4w\e#|
catch(Exception e){e.printStackTrace ();} 20;9XJmjl
,yYcjs!=o
FPDTw8" B;
Utility.log(nFileLength); I+8n;I)]X
YA4D?'
j<B9$8x&
return nFileLength; 7MKX`S
} 69g{oo
hy5[ L`B
]%' AZ`8
//保存下载信息（文件指针位置） AI-*5[w#A
private void write_nPos() ~zqb{o^pT
{ $F2Uv\7=
try{ _v,0"_"
output = new DataOutputStream(new FileOutputStream(tmpFile)); +xFn~b/
output.writeInt(nStartPos.length); r7m~.M+W"
for(int i=0;i<nStartPos.length;i++) *;Jb=
{ 9zu;OK%
// output.writeLong(nPos); P!eo#b^S
output.writeLong(fileSplitterFetch.nStartPos); BzzC|
output.writeLong(fileSplitterFetch.nEndPos); m\L`$=eO8
} =RQF::[h
output.close(); }aZuCe_
} WAa45G
catch(IOException e){e.printStackTrace ();} 95l)s],
catch(Exception e){e.printStackTrace ();} B>,eHXW
} )6OD@<r{
T6U/}&{O
i9;
//读取保存的下载信息（文件指针位置） D}_.D=)
private void read_nPos() `q^#u
{ C= ~c`V5>r
try{ `JySuP2~/
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :<QknU}dwy
int nCount = input.readInt(); "rv~I_zl
nStartPos = new long[nCount]; |N.2iN:
nEndPos = new long[nCount]; 8 #_pkVQw:
for(int i=0;i<nStartPos.length;i++) A3jxjQ
{ hyI7X7Hy
nStartPos = input.readLong(); Bn}woyJdx
nEndPos = input.readLong(); d54iZ`
} "tJ+v*E
input.close(); k# [!; <
} Nu5|tf9%A
catch(IOException e){e.printStackTrace ();} oz)[-
catch(Exception e){e.printStackTrace ();} ;J%:DD
} $R9D L^iD
NXW*{b
50,'z?-_
private void processErrorCode(int nErrorCode) K"#$",}=
{ GEc6;uz<
System.err.println("Error Code : " + nErrorCode); _D '(R
} YvR bM
AZj&;!}
eV9U+]C`
//停止文件下载 UcRP/LR%C
public void siteStop() "#Rh\DQ
{ ;tOsA #
bStop = true; I2Xd"RHN
for(int i=0;i<nStartPos.length;i++) g'"~'
fileSplitterFetch.splitterStop(); }w0pi
5ZCu6A
q+ax]=w
} LEb$Fd
} <kh.fu@.Q
//负责部分文件的抓取 p~D}Iyww1_
**FileSplitterFetch.java +|A`~\@N
*/ Rh>B# \
package NetFox; amBg<P`'_
#:K=zV\
T{{:p\<]_
import java.io.*; +VIA@`4
import java.net.*; o) )` "^
XT7m3M
K~W(ZmB
public class FileSplitterFetch extends Thread { 9YzV48su#
K-RmB4WI
*2AD#yIKC
String sURL; //File URL JEUU~L;
long nStartPos; //File Snippet Start Position "{q#)N
long nEndPos; //File Snippet End Position a"Qf
int nThreadID; //Thread's ID I)HO/i6>3
boolean bDownOver = false; //Downing is over "Q?+T:D8|
boolean bStop = false; //Stop identical 'zyw-1
FileAccessI fileAccessI = null; //File Access interface /%@;t@BK4
Qqm?%7A1
9+ 'i(q z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %rwvY`\
{ N' hT
this.sURL = sURL; XKp&GE@Y
this.nStartPos = nStart; JT+c7W7
this.nEndPos = nEnd; 7KC>?F
nThreadID = id; AuNUW0/ 7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H0l1=y
} EPm~@8@"j?
l\<.*6r
*22Vc2[i;
public void run() (r|m&/
{ nrac)W
while(nStartPos < nEndPos && !bStop) <PLAAh8
{ B[b>T=
Wjb_H (D
YT(N][V
try{ $1f2'_`8~
URL url = new URL(sURL); R%UTYRLUn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -WC0W
httpConnection.setRequestProperty("User-Agent","NetFox"); nFnM9 pdMK
String sProperty = "bytes="+nStartPos+"-"; 4@9Pd &I
httpConnection.setRequestProperty("RANGE",sProperty); $/wm k7T
Utility.log(sProperty); *,\v|]fc
I&-r^6Yx
*HoRYCL
InputStream input = httpConnection.getInputStream(); )/RG-L
//logResponseHead(httpConnection); CG1MT(V7?
1wFu3fh@
C;W@OS-;
byte[] b = new byte[1024]; M(X _I`\E
int nRead; B;k'J:-"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) __=53]jGE
{ ibkB>n{(
nStartPos += fileAccessI.write(b,0,nRead); eiMP:
//if(nThreadID == 1) Oeh A3$|#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A`7(i'i5]
} JK$3qUDnI
:nx+(xgw
>@vu;j\*E5
Utility.log("Thread " + nThreadID + " is over!"); 4=Th<,<
bDownOver = true; c p"K?)
//nPos = fileAccessI.write (b,0,nRead); u)@:V)z
} [)"\Aq
catch(Exception e){e.printStackTrace ();} ~F"S]
} Xm#W}Y'
} \U:OQ.e
+ktv:d
:\^b6"}8
//打印回应的头信息 DNGyEC
public void logResponseHead(HttpURLConnection con) ?%,LZw^[
{ T]th3*
for(int i=1;;i++) Spn[:u@
{ ]IV{;{E)
String header=con.getHeaderFieldKey(i); JSL&` `
if(header!=null) $;^|]/-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FX!KX/OE)
Utility.log(header+" : "+con.getHeaderField(header)); MG?,,8sO
else #)'Iqaq7
break; 505c(+
} }O\IF}X
} +La2-I
}m+Q(2
~Dt$}l-9
public void splitterStop() (OiV IH
{ riW9l6s'
bStop = true; 3t-STk?
} 4X^$"lM
k A3K
iq' PeVo
} x,C8):\t`B
a3 }V/MY
]N 9N][n
/* /?;'y,(Q
**FileAccess.java |R.yuSL)(
*//文件访问(定位，写) )K[\j?
package NetFox; b-ss^UL
import java.io.*; rd7p$e=i
r;{$x
BL&AZv/T
public class FileAccessI implements Serializable{ ,lH }Ba02F
5Npxs&Ea
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0`"oR3JY
RandomAccessFile oSavedFile; \Y!#Y#c
long nPos; @ujwN([I
-J3~j kf
\-yI dKj
public FileAccessI() throws IOException *Z#OfB4}
{ ,ayEZ#4.m
this("",0); QF/ULW0G!
} [mzed{p]]
Rq|6d M6H
# >k|^*\
public FileAccessI(String sName,long nPos) throws IOException eA7 Iv{M
{ !JXiTI!
oSavedFile = new RandomAccessFile(sName,"rw"); ulxlh8=
this.nPos = nPos; 1_t+lJI9j
oSavedFile.seek(nPos); n~UI47
} X$5
WO.u{vW]'
q;,lv3I
public synchronized int write(byte[] b,int nStart,int nLen) fHd[8{;P:
{ ktrIi5B
int n = -1; #][i!9$
try{ :EOai%i
oSavedFile.write(b,nStart,nLen); \96\!7$@O
n = nLen; xnMcxys~
} ?JZ$M
catch(IOException e) 1dLc/,|
{ wPM&N@Pf
e.printStackTrace (); Y'iI_cg
} I(^0/]'
cCZp6^/<x
%g@?.YxjT
return n; ~)f^y!PMQ
} d#E&,^@M
V<UChD)N`
Kkp dcc
} |^l_F1+w
zhw*Bed<
D<J'\mo
/* SxYz)aF~
**SiteInfoBean.java !}!KT(%%
*/ R0=f`;
package NetFox; G^Gs/- f
.~o{i_JH
@l CG)Ix<
public class SiteInfoBean { Q("m*eMRt
st)is4
b23A&1X
private String sSiteURL; //Site's URL P7-k!p"
private String sFilePath; //Saved File's Path ATkd#k%S
private String sFileName; //Saved File's Name I#MPJ@*WT
private int nSplitter; //Count of Splited Downloading File %!\=$s}g
:i!fPNn
Ln#o:"E
public SiteInfoBean() []A9j?_w
{//nSplitter的缺省值为5 [^ }$u[
//default value of nSplitter is 5 xq;>||B
this("","","",5); o:#jvi84F
} E.*hY+kGZ
zn>lF
|X=p`iz1&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {O>Td9
{ }K)AjZ
sSiteURL= sURL; N 8[rWJ#
sFilePath = sPath; c= t4 gf
sFileName = sName; us.[wp'Sh
this.nSplitter = nSpiltter; |>(Vo@
) 'xyK
2-'_Nwkl*
} )r.Wge
;:=j{,&dl[
K ar!
public String getSSiteURL() U1:m=!S;x
{ q%G[tXw
return sSiteURL; |y7TYjg6
} 7D<Aa?cv_l
m u9,vH
P1OYS\
public void setSSiteURL(String value) f1:>H.m`
{ oL~1M=r
sSiteURL = value; \Yj_U'2"i
} $@6q5Iz!&
#Tc`W_-
R>"pJbS;L
public String getSFilePath() J?{sTj"KB
{ ulALGzPh
return sFilePath; F7<M{h5s
} R7IFlQH%
<&[` +
qf K gNZ
public void setSFilePath(String value) cWnEp';.
{ Pm P&Qje7
sFilePath = value; NdJ]\>5oN,
} |m\7/&@<
#.u&2eyqQ
)r"R
public String getSFileName() F$i50s
{ vV"YgN:
return sFileName; .Od@i$E>&
} R}(Rv3>Xx
v"2A?
Y|mtQE?c
public void setSFileName(String value) GF@`~im
{ ih("`//nP
sFileName = value; lrPIXIM
} nd\$Y
s-6$C
}cUO+)!Y
public int getNSplitter() uWMSn
{ _$A?
return nSplitter; BV<_1WT}
} w?_'sP{pd
~9YEb
= <A0;
public void setNSplitter(int nCount) DQ$m@_/4w
{ >8>s K(S]
nSplitter = nCount; bOYM-\ {y
} ]/p>p3@1C
} +bso4 }rS
c;KMox/
tw 3zw`o:
/* 2ETv H~23
**Utility.java "KCG']DF
*/ 3 q8S
package NetFox; eF0FQlMe[
D @wIbU
v!DU ewz
public class Utility { Nj?Q{ztS
V~8]ag4
HOPl0fY$L
public Utility() lV./K;\T
{ Rm_+kp@\
@G>eCj
Dm?:j9o]g
} N3Q .4? z9
Ii3F|Vb G
//线程睡眠 ]T40VGJ:h
public static void sleep(int nSecond) B$OV^iwxK
{ h0x'QiCc
try{ i6FJG\d
Thread.sleep(nSecond); $WRRCB/A6
} x'G_z_<V
catch(Exception e) r0OP !u
{ r|z B?9Q
e.printStackTrace (); S%?%06$
} @5??`n
} #l*w=D?
aU.!+e%_
//日志 k8+U0J_{'
public static void log(String sMsg) benqm ~{\
{ b'4}=Xpn
System.err.println(sMsg); Y~r)WV!G
} 9[&q C
V<}chLd,
,l,q;]C%
public static void log(int sMsg) iTT7<x
{ =|fB":vk
System.err.println(sMsg); fG8^|:
} 7 > _vH]
} t3v_o4`&
Gy6x.GX
|~v2~
/* szqR1A
**TestMethod.java %n,_^voE
*/ zDxJK
package NetFox; e?o/H
XQOM6$~,
E2=vLI]
public class TestMethod { #Hl?R5
>C5u>@%9O
VHLNJnA
public TestMethod() kf95)iLo
{ ///xx/weblogic60b2_win.exe JPZH%#E(
try{ SoFl]^l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !@arPN$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oykb8~u}}
SiteFileFetch fileFetch = new SiteFileFetch(bean); JZ> (h
fileFetch.start(); (*T$:/zIS
} #oR@!?
catch(Exception e){e.printStackTrace ();} l?xd3Z@7[
rzvKvGd#N
MlbcJo3
} n7/&NiHxv/
?O]RQXsZ2
}YM[aq?6
public static void main(String[] args) =<K6gC27
{ [e{W:7uFV
new TestMethod(); ;R@D
} rz%^l1@-
} >4+KEK
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