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)); \Xt7`I<
} !N\@'F!
for(int i=0;i<nEndPos.length-1;i++) '8RsN-w
{ Bw)/DM]
nEndPos = nStartPos[i+1]; F#,90F'
} B4c]}r+
nEndPos[nEndPos.length-1] = nFileLength; ENl)Ts`y
} uB]7G0g:
} ~:rl=o}
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(Y.k8";)`
//启动子线程 G\/zkrxmv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yh@JXJ>
for(int i=0;i<nStartPos.length;i++) _JzEGpeG
{ b@gc{R}7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V%7WUq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oo/qb`-6
nStartPos,nEndPos,i); =t#llgi~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~9a<0Mc?
fileSplitterFetch.start(); j\[dx^\=
} )0.kv2o.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }>pknc?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8O5s`qKMYT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]}<}lI9
nEndPos = " + nFileLength); fIx+ILs
// fileSplitterFetch[nPos.length-1].start(); 4x=v?g&
%B2'~|g
$-OA'QwB]
//等待子线程结束 BM%e0n7
//int count = 0; APn|\
//是否结束while循环 m)ky*"(
boolean breakWhile = false; . oF &Ff/[
|sJ[0z
*.ll<p+(-
while(!bStop) y2Q&s9$Do
{ Maha$n*
write_nPos(); d\&U*=
Utility.sleep(500); /kZebNf6H
breakWhile = true; Dzpq_F!;V
z\\[S@>pt
gD-d29pQ
for(int i=0;i<nStartPos.length;i++) .9/hHCp
{ R$h<<v)%
if(!fileSplitterFetch.bDownOver) 7X`g,b!
{ 0#7>o^2
breakWhile = false; 0cv{
break; g+8OekzB5
} /QK6Rac-
} uanhr)Ys
if(breakWhile) 8l>?Pv
break; 6C1#/
J|W<;
1jmjg~W
//count++; JK7G/]j+Ez
//if(count>4) EKYY6S2
// siteStop(); P>y@kPi
} :(E@Gf
5N#aXG^9
A]_7}<<N
System.err.println("文件下载结束！"); pQyK={7?`
} oM X
catch(Exception e){e.printStackTrace ();} 5c@,bIl *
} >2Y=*K,:
]{;gw<T
^rB8? kt
//获得文件长度 ]}>2D,;
public long getFileSize() 6B8VfQ9[
{ z 4e7PW|
int nFileLength = -1; =Pyj%4Rs
try{ prUN)r@U
URL url = new URL(siteInfoBean.getSSiteURL()); P7[h-3+^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); frm>4)9+
httpConnection.setRequestProperty("User-Agent","NetFox"); lne|5{h
BwN0!lsF3
pE3?"YO
int responseCode=httpConnection.getResponseCode(); juP7P[d$qW
if(responseCode>=400) =eq[:K<6
{ :p1u(hflS
processErrorCode(responseCode); 7zl5yKN
return -2; //-2 represent access is error PF0_8,@U
} ^Y?k0z
#z'
mtpeRVcF
String sHeader; T )&A2q
[@_Jj3`4
Ucb F|vkI
for(int i=1;;i++) .y'>[
{ 1>.Ev,X+e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \:P>le'1
//Utility.log(in.readLine()); DcS+_>a\{l
sHeader=httpConnection.getHeaderFieldKey(i); lwR<(u31e
if(sHeader!=null) ]]HNd7Vh
{ 5p,RI&nlN
if(sHeader.equals("Content-Length")) W Tcw4
{ ;_XFo&@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K,tQ!kk
break; PioZIb/{
} ]HbY
} av(6wht8
else 3RUy,s
break; fQ7V/x!
} eYc$dPE
} 8%:Iv(UMk
catch(IOException e){e.printStackTrace ();} 2/U.|*mH
catch(Exception e){e.printStackTrace ();} qRu~$K
-D<< kra
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Utility.log(nFileLength); ynp8rf
5G}?fSQ>
Q1lyj7c#x
return nFileLength; M+oHtX$
} XjBW9a
05|=`eJ
)|ccX
//保存下载信息（文件指针位置） \a<wKTkn
private void write_nPos() hy9\57_#
{ 1l9G[o *
try{ Oz.HH
output = new DataOutputStream(new FileOutputStream(tmpFile)); UklUw
output.writeInt(nStartPos.length); _OYasJUMG
for(int i=0;i<nStartPos.length;i++) 2bz2KB5>
{ //B&k`u
// output.writeLong(nPos); ;2G*wR
output.writeLong(fileSplitterFetch.nStartPos); g%o(+d
output.writeLong(fileSplitterFetch.nEndPos); OUE(I3_
} }ZYd4h|g\z
output.close(); 3s*mbk[J
} `4r 3l S
catch(IOException e){e.printStackTrace ();} _9ao?:
catch(Exception e){e.printStackTrace ();} +tB=OwU%0
} ]IaMp788
~"gA,e-)
rV.}PtcFY
//读取保存的下载信息（文件指针位置） ` #0:gEo
private void read_nPos() ;J'LS
{ 1> ?M>vK
try{ n>z9K')
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xl{=Y< ;
int nCount = input.readInt(); >[f?vrz
nStartPos = new long[nCount]; hy1oq7F(Q
nEndPos = new long[nCount]; 'I|v[G$l
for(int i=0;i<nStartPos.length;i++) LPXi+zj
{ 39c2pV[
nStartPos = input.readLong(); g_E$=j92v
nEndPos = input.readLong(); ?PLPf>e
} . P viA
input.close(); I]|Pq
} oE@a'*.\
catch(IOException e){e.printStackTrace ();} ;T\%|O=Ke
catch(Exception e){e.printStackTrace ();} hXw]K"
} AhN4mc@
_1X!EH"
BX/8O<s0
private void processErrorCode(int nErrorCode) ?JbilK}a
{ +D6YR$_<
System.err.println("Error Code : " + nErrorCode); ';k5?^T
} W<{h,j8
|o"?gB}Dh
2F;y;l%
//停止文件下载 E#34Wh2z
public void siteStop() _>?\DgjH
{ k:i4=5^*GX
bStop = true; z9f-.72"X
for(int i=0;i<nStartPos.length;i++) /A\8 mL8
fileSplitterFetch.splitterStop(); 'd0~!w
810|Tj*U%
c?Y*Y
} AD>e?u
} :]K4KFM
//负责部分文件的抓取 Z9E\,Ly
**FileSplitterFetch.java E,Z$pKL?
*/ XTs8s12
package NetFox; _~m5^Q&
Q>qUk@
t|?ez4/{z
import java.io.*; j a[Et/r
import java.net.*; @/~omg}R
r wL`Czs
1dY}\Sp
public class FileSplitterFetch extends Thread { PN%zIkbo
^S<Y>Nm]
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String sURL; //File URL UBKu/@[f@
long nStartPos; //File Snippet Start Position n6=By|jRh
long nEndPos; //File Snippet End Position D>r&}6<
int nThreadID; //Thread's ID &A/]pi-\
boolean bDownOver = false; //Downing is over 0q
boolean bStop = false; //Stop identical wSL}`CgU
FileAccessI fileAccessI = null; //File Access interface 0|qAxR-
G&SB-
x^qVw5{n
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eu|YCYj)g
{ y8Ir@qp5
this.sURL = sURL; >h1}~jW+
this.nStartPos = nStart; hF?1y`20
this.nEndPos = nEnd; 1#g2A0U,
nThreadID = id; <V'@ks%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *-WpZGh
} hW')Sp
~\SGb_2
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public void run() $p8xEcQdU#
{ T~?Ff|qFC
while(nStartPos < nEndPos && !bStop) >{]%F*p4
{ G5_=H,Vmd
umfD>" ^I
M.D1XX1/
try{ 1nM #kJ"
URL url = new URL(sURL); ldcqe$7,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4KAZ ':
httpConnection.setRequestProperty("User-Agent","NetFox"); ;}WeTA_-[
String sProperty = "bytes="+nStartPos+"-"; mUC)gA/
httpConnection.setRequestProperty("RANGE",sProperty); PQt")[
Utility.log(sProperty); Mt|zyXyzX
L+F@:H6/0
f)rq%N &
InputStream input = httpConnection.getInputStream(); o|^3J{3G
//logResponseHead(httpConnection); %Xd[(Q)
5ta `%R_
(#c*M?g3
byte[] b = new byte[1024]; f`(UQJ
int nRead; M^Yh|%M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ja'T+!k
{ CkC^'V)
nStartPos += fileAccessI.write(b,0,nRead); uc{Ihw
//if(nThreadID == 1) g/_5unI}u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~At7 +F[
} XW H5d-
I|!OY`ko
hag$GX'2k
Utility.log("Thread " + nThreadID + " is over!"); P5V}#;v
bDownOver = true; \7eUw,~Q>
//nPos = fileAccessI.write (b,0,nRead); s[*rzoA
} #zy:a%
catch(Exception e){e.printStackTrace ();} ODN/G%l
} Wb_J(!da
} 2qNt,;DQ
@;4zrzQi7
<}Vrl`?h
//打印回应的头信息 7+cO_3AB
public void logResponseHead(HttpURLConnection con) C&f= ywi0
{ l30EKoul)
for(int i=1;;i++) Wi<m{.%\E
{ =s{>Fsm1
String header=con.getHeaderFieldKey(i); *Q.>-J<S
if(header!=null) =BeygT^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Jr4Ky<G_i
Utility.log(header+" : "+con.getHeaderField(header)); uZYF(Yu
else }tuC}
break; t3ZOco@~P
} XJB)rP
} gg/-k;@ Rf
iVr JQ
^CH=O|8j
public void splitterStop() 2'Uu:Y^
{ J{<X7uB
bStop = true; Hio0HL-
} S+6.ZZ9c
,THw"bm
{uFO/
} B mb0cFQ
V &T~zh1
MJ)RvNF
/* w.o@7|B1N
**FileAccess.java W i.&e
*//文件访问(定位，写) VGN5<?PrN
package NetFox; >6-`}G+|
import java.io.*; hfB%`x#akQ
}v{LRRi
$wa{~'
public class FileAccessI implements Serializable{ Vp\,CuQ
S13nL^=i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^DLfY-F+j
RandomAccessFile oSavedFile; 6|=f$a
long nPos; 2[yd> (`
/maJtX'
d1T!+I
public FileAccessI() throws IOException 4at?(B+
{ =svN#q5s
this("",0); ~8+ Zs
} @ q3k%$4
+`0k Fbx
M3y NAN
public FileAccessI(String sName,long nPos) throws IOException _LnpnL:
{ .Efk*
oSavedFile = new RandomAccessFile(sName,"rw"); (WJRi:NP?
this.nPos = nPos; Jpq~
oSavedFile.seek(nPos); djZqc5t
} T>Z<]s
:-Z2:/P
qR{=pR
public synchronized int write(byte[] b,int nStart,int nLen) hfTY.
{ ?^{Ah}x
int n = -1; Izc\V9+
try{ %1L,Y
oSavedFile.write(b,nStart,nLen); kD%( _K5
n = nLen; }8z?t:|S
} ]W!0$'o
catch(IOException e) !qg`/y9
{ q2j{tP#
e.printStackTrace (); >=>2m2z=
} v?$:@9pAk
:cECRm*
JbbzV>
return n; "sCRdx]_
} +\A,&;!SR
Qv-_ jZ
rlLMT6r.8
} C!!M%P
6 "sSoj
B9 uoVcW
/* yyJf%{
**SiteInfoBean.java !.gIHY
*/ ITBE|b
package NetFox; (ZizuHC
+'a^f5
!pW0qX\1n
public class SiteInfoBean { T^KKy0ZGM
59A}}.@?m
%> eiAB_b
private String sSiteURL; //Site's URL 7}>EJ
private String sFilePath; //Saved File's Path ki!0^t:9
private String sFileName; //Saved File's Name "^-a M
private int nSplitter; //Count of Splited Downloading File WT=;:j
~!L}yw
4VSU8tK|N]
public SiteInfoBean() Sm|6 %3
{//nSplitter的缺省值为5 VA5xp]
//default value of nSplitter is 5 CCx&7f
this("","","",5); Hn"RH1Zy
} 9A=,E&
4HlQ&2O%#
M2Qr(K|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (A#^l=su
{ VONDc1%ga
sSiteURL= sURL; eauF~md,
sFilePath = sPath; 0h_|t-9j
sFileName = sName; Y3b *a".X
this.nSplitter = nSpiltter; +0Y&`{#Z
=H8;iS2R
?tbrbkx
} ZE}}W_
:I#V.
&QgR*,5eo
public String getSSiteURL() Rm( "=(
{ }7Q%6&IR
return sSiteURL; 5b*C1HS@X
} 8ib:FF(= u
a~w$#fo"`f
W6Fo6a"<
public void setSSiteURL(String value) V,njO{Q
{ 7.oM J
sSiteURL = value; fHFE){
} y6a3tG
k(HUUH_z
|L ev.,,Ph
public String getSFilePath() %ET+iIhK
{ g7H(PF?
return sFilePath; 1qA;/-Zr<o
} /N{*"s2)
(LCfUI6;
})%{AfDRF
public void setSFilePath(String value) JZx[W&]zT
{ AwR=]W;j
sFilePath = value; 5H^(2w
} o]V^};B
F^:3?JA_
75lA%| *X
public String getSFileName() gbA_DZ
{ B+`g>h
return sFileName; CU0YIL
} ob]w;"
hZb_P\1X
:2`e(+Uz
public void setSFileName(String value) F== p<lrs
{ "tK=+f`NM
sFileName = value; PKz':_|
} {.Jlbi9!
gSj,E8-g
R;LP:,)
public int getNSplitter() OyIw>Wfv
{ "AqB$^S9t
return nSplitter; tH4B:Bgj!
} 2 %]X+`+O
AbM'3Mkz
HoAy_7-5
public void setNSplitter(int nCount) 2=}FBA,2
{ [-w%/D%@
nSplitter = nCount; Hl=xW/%6y
} 2\$oV
} BgT*icd8d
c71y'hnT
dE3) |%
/* |-H&o]
**Utility.java Id9TG/H7
*/ er\|i. Y
package NetFox; L~3Pm%{@A
0jfuBj5!
4+tEFxvX&
public class Utility { 4qa.1j(R/
U<XG{<2
"dlVk~
public Utility() x{n=;JD
{ ;Rf'P}"]
zQ PQ
E{(;@PzE
} xIn:ZKJ'
e3\T)x&=
//线程睡眠 !,PWb3S
public static void sleep(int nSecond) j>kqz>3
{ `]aeI'[}R
try{ i XN1I
Thread.sleep(nSecond); \=o-
} wd6owr
catch(Exception e) &^nGtW%a 9
{ vDvFL<`vmD
e.printStackTrace (); nk:)j:fr
} hbn([+xY
} \M-OC5fQv
O/LXdz0B
//日志 2an f$^[
public static void log(String sMsg) <VE@DBWyl~
{ dRMx[7jVA
System.err.println(sMsg); :Dp0?&_
} F'Z,]b'st3
\2z>?i)
)/P}?`I
public static void log(int sMsg) }m8q}~>tL
{ uAk.@nfiEv
System.err.println(sMsg); ?7A>+EY
} aq-~B~c`g
} GvAb`c=
xz]~ jL@-]
a'T;x`b8U,
/* dr"1s-D4IQ
**TestMethod.java x1a:u
*/ fQFk+C
package NetFox; XPPdwTOr
'%;m?t%q
nt<]d\o0
public class TestMethod { PY'2h4IL
y7<|_:00
@)}L~lb[)
public TestMethod() Y-9I3?ar
{ ///xx/weblogic60b2_win.exe &5;"#:ORcK
try{ (k P9hcV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (m$Y<{)2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +`15le`R
SiteFileFetch fileFetch = new SiteFileFetch(bean); *WZA9G#V5
fileFetch.start(); 4ppz,L,4
} JGZBL{8
catch(Exception e){e.printStackTrace ();} n"8Yv~v*2j
EX"yxZ~
4Tc~b3\!Y
} )%]J>&/0J
3' 'me
IGgL7^MF
public static void main(String[] args) ,: ^u-b|
{ ~"bVL[
new TestMethod(); iDD$pd,e\
} fV~~J2IK
} _v:SP LU
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