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)); D"(L5jR8m@
} g[RI.&?
for(int i=0;i<nEndPos.length-1;i++) S{pXs&4O
{ ~c^>54
nEndPos = nStartPos[i+1]; e}/Lk5q!
} &s Pq<lo
nEndPos[nEndPos.length-1] = nFileLength; Z>c3
} gxz-R?.
} m7a#qs;,
hI%bjuq
^bg2[FV
//启动子线程 LEMfG~Czq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VVH.2&`I
for(int i=0;i<nStartPos.length;i++) Unj.f>U
{ voP7"Dl[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wN1niR'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |8>3`w!
nStartPos,nEndPos,i); [[PEa-992
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); poGc a1
fileSplitterFetch.start(); !tfb*@{;'
} IW 21T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U*Ge<(v$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m8'C_U^89
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ];'v8)Y
nEndPos = " + nFileLength); \%PaceH
// fileSplitterFetch[nPos.length-1].start(); 1XM^8 .;
ku$$ 1xq
S}APQ
//等待子线程结束 JD@J[YY5R
//int count = 0; 2 rw%H
//是否结束while循环 1) ta
boolean breakWhile = false; BdlVabQyKW
7K)6^r^
mxb(<9O
while(!bStop) i1H\#;`$
{ 3)-/`iy#
write_nPos(); .ObZ\.I
Utility.sleep(500); u6>?AW1~
breakWhile = true; G!K]W:m
hX`}Q4(k
C<KrMRWh^
for(int i=0;i<nStartPos.length;i++) (Yp+bS(PU*
{ %K(<$!
if(!fileSplitterFetch.bDownOver) pw7[y^[Qg
{ @u==x*{|
breakWhile = false; 'F>'(XWWQ
break; NR;1z
} ml\4xp,
} G}&Sle]
if(breakWhile) tOfg?)h{dc
break; \j&^aAp r
UnI48Y
7AYd!n&S
//count++; 0-~\ W(
//if(count>4) X]\ \,
// siteStop(); :_!8 WB
} ^G6RjJxqp8
vAyFmdJ^
CPNL 94x
System.err.println("文件下载结束！"); >3z5ww
} &u#&@J
catch(Exception e){e.printStackTrace ();} pdE3r$C
} ?LvCR_D:
zZVfj:i8
z dO#0tN
//获得文件长度 PRz/inru-
public long getFileSize() p.LFVFPT
{ v\p;SwI
int nFileLength = -1; \&H nKhI
try{ *S/_i-ony
URL url = new URL(siteInfoBean.getSSiteURL()); H$I=W>;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L!=QR8?@E
httpConnection.setRequestProperty("User-Agent","NetFox"); ~gGZmTb
4:U?u
_i/t?7
int responseCode=httpConnection.getResponseCode(); _YF%V;X
if(responseCode>=400) `FoxP
{ 7Hm3;P.
processErrorCode(responseCode); (V4 ~`i4V
return -2; //-2 represent access is error &hRvol\J
} xO-+i\ ZV
y~)1 1]'>
aH^RoG}
String sHeader; &^W|iXi#
I1PuHf Qs
=}.EY iD
for(int i=1;;i++) Dk?\)lD`
{ 4'0Dr++
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qK)73eNSR
//Utility.log(in.readLine()); DZi!aJ
sHeader=httpConnection.getHeaderFieldKey(i); o865(<p
if(sHeader!=null) 5}`_x+$%(`
{ M)U{7c$c7
if(sHeader.equals("Content-Length")) 3YVi" k?2
{ -|E!e.^7:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OoWyPdC+P
break; .k,kTr$S
} 'Fmvu
} o<N nV
else EVoEszR
break; TYy.jFT-
} V{JAB]?^
} 6L)%T02C
catch(IOException e){e.printStackTrace ();} s0PrbL%_`
catch(Exception e){e.printStackTrace ();} ^Vpq$'!
i9/aAH0
nw-I|PVTNa
Utility.log(nFileLength); ]C) 4
?mwD*LN3o
92EWIHEWZ
return nFileLength; Z?\2F%
} }mAa}{_
rb|U;)C
p\<u6v ~J
//保存下载信息（文件指针位置） %"P,1&\^
private void write_nPos() Dc_yM
{ @;'o2
try{ C+TI]{t
output = new DataOutputStream(new FileOutputStream(tmpFile)); P'`r
output.writeInt(nStartPos.length); \_lod kf
for(int i=0;i<nStartPos.length;i++) Rj4|Q:XG
{ E@ESl0a;
// output.writeLong(nPos); .FLy;_f+
output.writeLong(fileSplitterFetch.nStartPos); qTqwPWW*
output.writeLong(fileSplitterFetch.nEndPos); rwI
} t2lS ~l)
output.close(); <WcR,d
} U-|NY
catch(IOException e){e.printStackTrace ();} uXKERzg
catch(Exception e){e.printStackTrace ();} >k'c'7/
} jrS[f
l g-X:Z.
{DR`;ea])1
//读取保存的下载信息（文件指针位置） [<6S%s
private void read_nPos() Cvf[/C+
{ B#M5}QT|2
try{ u,UmrR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |]c8jG\h
int nCount = input.readInt(); DK$s&zf
nStartPos = new long[nCount]; Qc pm!
nEndPos = new long[nCount]; R;j!}D!4
for(int i=0;i<nStartPos.length;i++) :AE&Ny4
{ <>8WQn,K
nStartPos = input.readLong(); c`o7d)_Ke
nEndPos = input.readLong(); 'nwx9]q
} ~x|F)~:0=
input.close(); w'm;82V:P-
} /C6k+0ApMT
catch(IOException e){e.printStackTrace ();} N|6MP e
catch(Exception e){e.printStackTrace ();} {QwHc5Bf
} @0F3$
=W"F[fD
+1D+]*t_?[
private void processErrorCode(int nErrorCode) 3nhXZOO1
{ HBMhtfWW
System.err.println("Error Code : " + nErrorCode); i{`;R
} GgB,tam{p
zR{W?_cV
xLC3>>P
//停止文件下载 jJ5W>Q1mK$
public void siteStop() [Lzw#XE
{ oomT)gO 6*
bStop = true; Gy6l<:;
for(int i=0;i<nStartPos.length;i++) } x2DT8u
fileSplitterFetch.splitterStop(); fc |GArL#}
@CT;g\4
FGoy8+nB1M
} _iir<}
} dzDqZQY$
//负责部分文件的抓取 v^1pN>#%g
**FileSplitterFetch.java +w+}b^4
*/ r_-_a(1R:
package NetFox; pNKhc#-w
kYjGj,m"
|%' nVxc4r
import java.io.*; Ym =FgM\
import java.net.*; 3yB!M
6e[VgN-s
lw<c2C
public class FileSplitterFetch extends Thread { [@5Ytv H
5.MGaU^Z$
sk=-M8;\
String sURL; //File URL |v$JCU3!A
long nStartPos; //File Snippet Start Position #3+!ee27#
long nEndPos; //File Snippet End Position TL}++e 7+
int nThreadID; //Thread's ID '7iSp=
boolean bDownOver = false; //Downing is over )3>hhuaa
boolean bStop = false; //Stop identical {qN 5MsY
FileAccessI fileAccessI = null; //File Access interface c1E'$- K@
6x%h6<#xh*
id1s3b;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,&R/4:I
{ -}KC=,]vh
this.sURL = sURL; @*6 C=LL
this.nStartPos = nStart; Z7=`VNHc
this.nEndPos = nEnd; `.i!NBA'6
nThreadID = id; xo7Kn+ Kl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `|ASx8_!
} :(M(>4t
"CI=`=
ZOZ+Y\uU
public void run() eep1I :N
{ opc/e
while(nStartPos < nEndPos && !bStop) ~NpA".PB
{ [O?z@)dx
5nKj )RH7M
R5X.^u
try{ BEre*J
URL url = new URL(sURL); 1f":HnLRM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3ZXQoC '
httpConnection.setRequestProperty("User-Agent","NetFox"); hMykf4
String sProperty = "bytes="+nStartPos+"-"; TztAZ2C
httpConnection.setRequestProperty("RANGE",sProperty); /(.mp<s0
Utility.log(sProperty); W7 #9jo
p_${Nj
=g|IG [V
InputStream input = httpConnection.getInputStream(); Bg|5KOnd
//logResponseHead(httpConnection); .P7"e5ge
(A~/'0/
Z2'Bk2 L
byte[] b = new byte[1024]; 1$p2}Bf{n
int nRead; Q|D @Yd\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IVAmV!.z
{ =AEBeiz
nStartPos += fileAccessI.write(b,0,nRead); LC'{p
//if(nThreadID == 1) \cUC9/ b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O8j_0
} g.zEn/SM
i5CK*"$Q
z$?~Y(EY
Utility.log("Thread " + nThreadID + " is over!"); 8j=}u/T@F
bDownOver = true; *fn*h[pV&
//nPos = fileAccessI.write (b,0,nRead); u (em&M
} &8g?4v
catch(Exception e){e.printStackTrace ();} LQngK7>
} 8q,6}mV
} 4Dw@r{
98uV6b~g
G"Sd@%W(
//打印回应的头信息 VrxQc qPr`
public void logResponseHead(HttpURLConnection con) 2-C!jAfd
{ wv\w;'
for(int i=1;;i++) L;'"A#Pa
{ ]y1OFKYv
String header=con.getHeaderFieldKey(i); Vp3ZwS
if(header!=null) h3z{(-~y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?6fnpGX@a
Utility.log(header+" : "+con.getHeaderField(header)); _YLfL
else M>i9i-dU
break; >76\nGO
} A8oo@z68n>
} ng_^
y*tZ !m2Gg
C ihAU"
public void splitterStop() /p+>NZ"b
{ -8j+s}Q
bStop = true; ,u`YT%&L
} ,z-}t& _t
K%F,='P}
AigS!-
} S/ODqL|
nysUZB
OVhE??#
/* 9/ibWa\.
**FileAccess.java \8?Tdx=
*//文件访问(定位，写) a6WI170^1
package NetFox; /iJ4{p
import java.io.*; c%'RR?Tl
%|oJ>+
b/{t|io{
public class FileAccessI implements Serializable{ D-4f >
7zSLAHW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 or';A'k
RandomAccessFile oSavedFile; i5K[>5
long nPos; F=a<~EpZ
}A7j/uy}s
iTAx=SG
public FileAccessI() throws IOException sSi6wO$
{ Ft;^g3N
this("",0); f'VX Y-
} i-6F:\;
+E.GLn2/
<oX7P69
public FileAccessI(String sName,long nPos) throws IOException !WpBfd>v.I
{ h >s!K9
oSavedFile = new RandomAccessFile(sName,"rw"); BC&9fr
this.nPos = nPos; 8_tK4PwP
oSavedFile.seek(nPos); HY%i`]4X
} ~R26
p%R
.[JYj(p
public synchronized int write(byte[] b,int nStart,int nLen) <\pfIJr$
{ t<|NLk.
int n = -1; MgNU``
try{ j&Wl0
oSavedFile.write(b,nStart,nLen); (r D_(%o
n = nLen; Ou1JIxZ)|
} }0X:F`Y-
catch(IOException e) %+K<<iyR|
{ ek}a}.3 {
e.printStackTrace (); Wu_kx2h
} 9)gC6IiW
LG1r]2
)Hk3A$6(
return n; Hr]h Jc
} nw<&3k(g}
iCcB@GlA
}XSfst5-H
} HAJ7m!P
8peDI7[|
\DD0s8
/* thvYL.U:
**SiteInfoBean.java q11>f
*/ tGl;@V@Qj
package NetFox; 3 "Q=Vl"
[>1OJY.S}T
2U:H545]]
public class SiteInfoBean { p-/|mL
Y5FbU
(3#Cl 1]f
private String sSiteURL; //Site's URL 4W)B'+ZK8
private String sFilePath; //Saved File's Path ^n"OL*ipG
private String sFileName; //Saved File's Name Bxfc}vC.
private int nSplitter; //Count of Splited Downloading File yzLpK;
JMz;BAHT
7e#?e+5+A
public SiteInfoBean() yA.4G_|I
{//nSplitter的缺省值为5 T|dY 2
//default value of nSplitter is 5 ]5$eAYq
this("","","",5); H+ 0$tHi
} 6^"=dn6K
'toa@5
24)(5!:"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Qe}`~a9P
{ Xp8]qH|K
sSiteURL= sURL; vL\&6n~M>
sFilePath = sPath; yLdVd P
sFileName = sName; $}=krz:r
this.nSplitter = nSpiltter; (s7;^)}zx
lobGj8uxq
75T7+:p
} B,@c;K
]):<ZsT
5i1>I=N
public String getSSiteURL() mqAWL:VvQ7
{ :xh?eN&
return sSiteURL; d_)o
} ,>eMG=C;g
0\@dYPa&C
Y))u&*RuT0
public void setSSiteURL(String value) `9uB~LY^i
{ k25WucQ
sSiteURL = value; #&m0WI1
} o;=l^-
dUF&."pW e
7"w2$*4'0
public String getSFilePath() 3`B6w$z>(
{ n;$5Cq!v=
return sFilePath; ?kZTI (
} "9^j.
)6Ny1x+
00SbH$SU
public void setSFilePath(String value) 1}:bqI.<W
{ _:-ha?W$;y
sFilePath = value; LX@/RAd vz
} '`XX "_k3
PG_0\'X)/w
HN.3
public String getSFileName() u\LFlX0sO
{ q|v(Edt|_[
return sFileName; ]"1`+q6i
} I-WhH>9
0em#-*|2"
KA){''>8
public void setSFileName(String value) & M~`:R
{ LF~*^n>
sFileName = value; Ircp``g
} e|p$d:#!
USVqB\#
KTn}w:+B\
public int getNSplitter() $T`<Qq-r
{ =ZDAeVz3w
return nSplitter; {e[c
} DWID$w
t@R ?Rgu3
-GqT7`:(H4
public void setNSplitter(int nCount) ltgc:&=|@
{ *r=:y{!Yd
nSplitter = nCount; Gu'rUo3Do
} Pj4/xX
} *+\SyO
SnFk>`
o4%y>d)
/* g"?Y+j
**Utility.java 59%tXiO
*/ wmTq` XH)
package NetFox; l"!Ko G7
\uXcLhXN
j~+>o[c
public class Utility { g-e#!(
A%^w^f
F@*+{1R
public Utility() rN%F) q#
{ *_KFW@bC:
,WG<hgg-U)
xw3YK!$sIF
} m^#rB`0;L
Z0*ljT5|
//线程睡眠 TP"1\O
public static void sleep(int nSecond) n#:N;T;\a
{ ~",`,ZXQy
try{ ]Lm9^q14m
Thread.sleep(nSecond); 7yx$Nn`(
} >A<bBK#
catch(Exception e) }>'PT-
{ #~=hn8
e.printStackTrace (); <]T`3W9
} gCN$}
} Qed.4R:o
4mHvgnT!WA
//日志 GG0R}',0
public static void log(String sMsg) Q\WC+,_%
{ DF g,Xa#
System.err.println(sMsg); h^*4}GU
} 2l F>1vH
2Y>~k{AN%
$YXMI",tt<
public static void log(int sMsg) 7As|Ns`
{ v9D22,K-
System.err.println(sMsg); x&`~R>5/
} h[?O+Z^
} *$"gaXI
|0\0a&tkPl
Hw|AA?,0-
/* =e}H'5?!
**TestMethod.java "n: %E
*/ RKa}$ 7
package NetFox; ZWm8*}3]7_
!TP@- X;
1=nUW":
public class TestMethod { Qq@G\eRo
9Li%KOY
+E;2d-x*p
public TestMethod() sU"}-de
{ ///xx/weblogic60b2_win.exe cwuO[^S}
try{ I`w4Xrd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U|5nNiJM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =fYL}m5E
SiteFileFetch fileFetch = new SiteFileFetch(bean); PT^c^{V
fileFetch.start(); AxZD-|.
} @_"9Dy Y%
catch(Exception e){e.printStackTrace ();} O4g+D#Lu
s (0*
xy<`#
} 90# ;?#
I"t(%2*q
v @O&t4
public static void main(String[] args) V=X:=
{ ; h`0ir4[A
new TestMethod(); )m&U#S _;
} H%1$,]F
} k`{@pt.
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