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)); /vl]Oa&U
} !<!sB)
for(int i=0;i<nEndPos.length-1;i++) kSH3)CC P
{ ={?}[E
nEndPos = nStartPos[i+1]; O/wl";-
} I72UkmK`
nEndPos[nEndPos.length-1] = nFileLength; Z1FO.[FV
} zi23k=
} N7%+n*Z
5r<%xanXW/
"-y\F}TE
//启动子线程 oW-Tw@D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N5rY*S
for(int i=0;i<nStartPos.length;i++) C+Wb_
{ "aN<3b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GdavCwJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )^uLZMNaI
nStartPos,nEndPos,i); $jb0/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #D3e\(
fileSplitterFetch.start(); Hw5\~!FX
} 0}qij
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PKR0y%Ar
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "_ b Sy
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PNXZ3:W
nEndPos = " + nFileLength); J.:"yK""
// fileSplitterFetch[nPos.length-1].start(); >\K<q>*
/d5_-AB(v
a\\B88iRRZ
//等待子线程结束 kwdmw_
//int count = 0; ^ 3LM%B
//是否结束while循环 h)q:nlKUW
boolean breakWhile = false; PG9won5_
$Trkow%F]
=1lKcA[z
while(!bStop) g/so3F%v .
{ -9/YS
write_nPos(); 9U6y<X
Utility.sleep(500); 6rL'hB!!]*
breakWhile = true; j4le../N
GEwgwenv
TH/!z,(>
for(int i=0;i<nStartPos.length;i++) yw5MlZ4P=
{ 4hztYOhJ{
if(!fileSplitterFetch.bDownOver) epm t
{ M|FwYF^
breakWhile = false; +&tY&dQQB
break; K;G1cFFyG
} f3U#|(%(*
} ;C-5R U V
if(breakWhile) bslv_OxJ
break; BnqAv xX
=2bW"gs I
q|om^:n.
//count++; TQ" [2cY
//if(count>4) AynWs5|z=
// siteStop(); |!dyk<}oIu
} m~r^@D
A$A7F=x
2Ua_7
System.err.println("文件下载结束！"); \P!v9LX(
} a2UER1Yp"
catch(Exception e){e.printStackTrace ();} TclZdk]%T
} g8mVjM\B;
[+gX6
>DQl&:-)t
//获得文件长度 7'j?GzaQ+
public long getFileSize() HGB96,o f9
{ 4XQv
int nFileLength = -1; iBxCk^
try{ gGN[AqR
URL url = new URL(siteInfoBean.getSSiteURL()); WW@/q`h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jfl7L"2
httpConnection.setRequestProperty("User-Agent","NetFox"); AZorzQ]s
u~Q0V J~
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int responseCode=httpConnection.getResponseCode(); 'rHkJ
if(responseCode>=400) w@.E}%bwq
{ A2Rr*e
processErrorCode(responseCode); b0x9}
return -2; //-2 represent access is error 2j H`
} Tx0/3^\>8A
17H_>a\`
!li Q;R&
String sHeader; :^3MN
5h+g^{BE
.Q?cNSWU
for(int i=1;;i++) 5)V J
{ )& %X AW{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [f.[C5f%"'
//Utility.log(in.readLine()); (p68Qe%OuG
sHeader=httpConnection.getHeaderFieldKey(i); Lh"Je-x<<
if(sHeader!=null) @= 6}w_
{ O\XN/R3
if(sHeader.equals("Content-Length")) ,y,NVF
{ VGM8&J{o'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h -+vM9j
break; !zvKl;yT
} ;_of'
} waQNX7Xdn
else HvK<>9
break; E92dSLhs5
} <y6M@(b
} :r:5a(sq
catch(IOException e){e.printStackTrace ();} v(FO8*5DZ
catch(Exception e){e.printStackTrace ();} Dq*>+1eW2
~!,'z
'7 6}6G%
Utility.log(nFileLength); nBaY|
q*@7A6:FV>
YQ4;X8I`r
return nFileLength; xRP#}i:m
} /t%IU
??aOr*%
<QugV3e
//保存下载信息（文件指针位置） !a~>;+
private void write_nPos() MT$OjH'Q`
{ ^]Lr_k
try{ 7}%3Aw6]S
output = new DataOutputStream(new FileOutputStream(tmpFile)); a>.2Q<1
output.writeInt(nStartPos.length); w%VHq z$
for(int i=0;i<nStartPos.length;i++) 4B<D.i ;}
{ K4N~ApLB+
// output.writeLong(nPos); 45edyQ
output.writeLong(fileSplitterFetch.nStartPos); |`U^+Nf
output.writeLong(fileSplitterFetch.nEndPos); !?Z}b.%W
} ,78QLh9:
output.close(); my[)/'
} niFX8%<hP
catch(IOException e){e.printStackTrace ();} UALwr>+VJ
catch(Exception e){e.printStackTrace ();} {w(6Tc
} 7cr+a4T33
T}$1<^NK
Mm:6+
//读取保存的下载信息（文件指针位置） un6grvxr
private void read_nPos() pYI`5B4
{ Od>Ta_
try{ SvAz9>N4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :'f#0ox
int nCount = input.readInt(); aa.EtKl
nStartPos = new long[nCount]; S$%T0~PR~
nEndPos = new long[nCount]; #v=hiL
for(int i=0;i<nStartPos.length;i++) ]"q)X{G(+
{ :upi2S_e
nStartPos = input.readLong(); -G(z!ed
nEndPos = input.readLong(); %8yfFrk
} ?Re@`f+*
input.close(); +Ys<V
} ?c+_}ja,
catch(IOException e){e.printStackTrace ();} f/&Dy'OV7
catch(Exception e){e.printStackTrace ();} Aw;~b&.U{_
} gZM\RJZ_
SM@l4GH
it,i^32|
private void processErrorCode(int nErrorCode) -F/"W
{ Z$k4T$,[-
System.err.println("Error Code : " + nErrorCode); ?M;2H{KG:
} ^p|MkB?uM
FdKp@&O+1
245(ajxHC
//停止文件下载 bkceR>h%
public void siteStop() &0It"17Ej
{ @7"xDgA
bStop = true; yj `b-^$?
for(int i=0;i<nStartPos.length;i++) "k)( ,
fileSplitterFetch.splitterStop(); mF%>pj&b
H(lq=M0~
`D>PU@s$nT
} bDeHU$
} TixHEhw
//负责部分文件的抓取 gkI(B2,/
**FileSplitterFetch.java mSY;hJi
*/ g*N~r['dZ
package NetFox; NC>rZS]
% rRYT8
RN5\,>+
import java.io.*; .YYiUA-i9n
import java.net.*; PM=Q\0
,LSF@1|Fx
(i.MxGDd
public class FileSplitterFetch extends Thread { ]N*q3y|)
]\v'1m"
drBWo|/
String sURL; //File URL `a["`N^
long nStartPos; //File Snippet Start Position lV?rC z
long nEndPos; //File Snippet End Position )xiic3F
int nThreadID; //Thread's ID H\Y.l,^
boolean bDownOver = false; //Downing is over )p~\lM}?d
boolean bStop = false; //Stop identical |<\o%89AM
FileAccessI fileAccessI = null; //File Access interface 7Z0 )k9*
~Hd{+0
Ih;6(5z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `ihlKFX
{ `pn]jpW9
this.sURL = sURL; TKx.`Cf m
this.nStartPos = nStart; 7ib~04
this.nEndPos = nEnd; O/e5LA
nThreadID = id; Gx|$A+U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jF<Y,(C\
} 1tDd4r?Y
m>x.4aO1
\;&j;"c,W
public void run() 54_CewL1P]
{ =W.b7 6_
while(nStartPos < nEndPos && !bStop) fZ`b~ZBwIj
{ xlp^XT6#
@N7X(@O
MOP/q4j[
try{ 'VS!<
URL url = new URL(sURL); W#P)v{K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ``nuw7\C:
httpConnection.setRequestProperty("User-Agent","NetFox"); -7fsfcGM$
String sProperty = "bytes="+nStartPos+"-"; /+1+6MqRn*
httpConnection.setRequestProperty("RANGE",sProperty); p(8H[L4Y
Utility.log(sProperty); R(74Px,/
>)=FS.?]
H1yl88K
InputStream input = httpConnection.getInputStream(); mQ;b'0&
//logResponseHead(httpConnection); M n`gd#
rZLTai}`>
|_&vW\
byte[] b = new byte[1024]; +XLy Pj
int nRead; w,SOvbAxX2
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J/>Y mi,
{ jmxjiJKP
nStartPos += fileAccessI.write(b,0,nRead); btkD<1{g
//if(nThreadID == 1) :;cKns0OA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); = 7d{lK
} "a6[FqTs
^GQ+,0Yy
BD&JbH!(
Utility.log("Thread " + nThreadID + " is over!"); 3V?JX5X\
bDownOver = true; G#t!{Q}8
//nPos = fileAccessI.write (b,0,nRead); &#;vR0O
} Z `sM(?m
catch(Exception e){e.printStackTrace ();} N\ChA]Ck
} a[Ah
} 5D8V)i
@Hw#O33/'
=Bcwd7+
//打印回应的头信息 {u{n b3/jl
public void logResponseHead(HttpURLConnection con) U$Z)v1&{
{ mHrt)0\_
for(int i=1;;i++) >'iXwe-
{ L9M0vkgri
String header=con.getHeaderFieldKey(i); ;{[&&qMwU
if(header!=null) wHq*)7#h#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >B<jR$`6@
Utility.log(header+" : "+con.getHeaderField(header)); W&#Ps6)8
else [#`)Bb&w
break; bgq/]fI}
} bCHJLtDQ
} m/Ou$
cK%Sty'8+
.|^L\L(!
public void splitterStop() 1v)ur\>R
{ m^Qc9s#D
bStop = true; \2KwF}[m
} 48vKUAzx`
S+ gzl#r
)ZC0/>R
} .;&c<c|
FpN>T
89e<,f`h
/* -L%tiz`_
**FileAccess.java 3qwi)nm
*//文件访问(定位，写) w/BaaF.0
package NetFox; _^]2??V
import java.io.*; -7,xjn
[vh&o-6
MKzIY:ug
public class FileAccessI implements Serializable{ <Dojl #
5V5Nx(31i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .`*h2
RandomAccessFile oSavedFile; g\^7Q
long nPos; "i0{E!,XL
,j\1UAa
r#hA kOw
public FileAccessI() throws IOException OZ##x
{ ,'w9@A
this("",0); f|Dq#(^\
} *gF8"0s
O(q1R#n-}+
D32~>J.F
public FileAccessI(String sName,long nPos) throws IOException '*gY45yT`
{ n=Qz7N(M
oSavedFile = new RandomAccessFile(sName,"rw"); !o+[L
this.nPos = nPos; 6/e+=W2
oSavedFile.seek(nPos); zr#n^?m
} Iow45R~]
7bJAOJ'_
xh|NmZg
public synchronized int write(byte[] b,int nStart,int nLen) _voU^-
{ 21ng94mC
int n = -1; 0 ~K4vSa
try{ |uL"/cMW7
oSavedFile.write(b,nStart,nLen); :+Ti^FF`w
n = nLen; r0jhIE#
} {}x{OP
catch(IOException e) ~Y;_vU
{ "A?&`}%
e.printStackTrace (); K6 D3
} 86+nFk
bz$)@gLc
N;N,5rxV
return n; 4FLL*LCNX
} (NB\wJg $
G_OLUuK?C
mtfEK3?2*
} NABVU0}
nz-( 8{ae
@px4[
/* V% -wZL/
**SiteInfoBean.java =VXxQ\{
*/ QxUsdF?p
package NetFox; SA3!a.*c
W<']Q_su
]H[%PQ r`Z
public class SiteInfoBean { ";vP77|m7R
;F3#AO4(
2g'o5B\*
private String sSiteURL; //Site's URL ?VM4_dugf
private String sFilePath; //Saved File's Path 8":O\^i
private String sFileName; //Saved File's Name _pZ2^OO@
private int nSplitter; //Count of Splited Downloading File gxa@da
2o5Pbdel
~# ~XDcc
public SiteInfoBean() (Qf"|3R4
{//nSplitter的缺省值为5 d9bc>5%-F
//default value of nSplitter is 5 {[W [S@+
this("","","",5); %v)m&VUi%
} ( q8uB
qC|$0
q,ur[ &<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) JIJ79HB
{ P`ZYm
sSiteURL= sURL; ;~nz%LJ
sFilePath = sPath; svT1b'=\$I
sFileName = sName; Gh.@l\|tf
this.nSplitter = nSpiltter; 7|vB\[s
;`CNe$y
T1Gy_ G/
} FEoH$.4
;giW
e/S^Rx4W
public String getSSiteURL() +#$(>6Zu"{
{ !/]vt?v#^
return sSiteURL; E 0k1yA
} J|Af`HJ
.WeP]dX%:f
o>G^)aRa
public void setSSiteURL(String value) /C: rr_4=
{ FXF#v>&
sSiteURL = value; zG%ZDH^82_
} 'OERW|BO
Z3jtq-y
ueimTXk
public String getSFilePath() aC9PlKI
{ S zqY@
return sFilePath; BkO)hze
} C{"uz_Gh
+|SvJ
Po+tk5}''5
public void setSFilePath(String value) c<T'_93
{ VlLc[eVV
sFilePath = value; !"dn!X
} 9[L@*7A`m
?M02|8-
]t'bd<O
public String getSFileName() Y$L>tFA
{ @1p,
return sFileName; ,vN0Jpf}\8
} \q |n0>
@qGg=)T
vWM'}(
public void setSFileName(String value) [+j39d.Q
{ #c2InwZV
sFileName = value; s3., N|
} L.]mC!
9F*],#ng
|ULwUi-r
public int getNSplitter() 1zz.`.R2U
{ eqFOPK5q
return nSplitter; a%h'utF{[
} #_zd`s3k
Qey6E9eCA
C6"bGA
public void setNSplitter(int nCount) 4Pm+0=E
{ Aj22t
nSplitter = nCount; [;]@PKW?w
} $ZQ?E^> B
} $!msav
e1k\:]6
cuw3}4m%
/* OR\-%JX/5
**Utility.java 0lvX,78G;
*/ VB?mr13}G
package NetFox; +]!`>
qZ39TTQ*p
JMT?+/Qbu
public class Utility { kOe~0xoT@u
.W>8bg'u9
7%(|)3"V
public Utility() B-OuBS,fwC
{ X> *o\
j&S8x|5
jgr2qSUC
} >v+ia%o
-}ebn*7i\
//线程睡眠 I)-u)P?2x
public static void sleep(int nSecond) LqHeLN
{ aoZ`C3
try{ ?Z<2zm%qV
Thread.sleep(nSecond); R.g'&_zx
} kRk=8^."By
catch(Exception e) zn4Yo
{ t?-7Z6
e.printStackTrace (); j=^b'dyL
} J6!t"eB+
} }/Wd9x
g>[|/z P
//日志 W biUz2)
public static void log(String sMsg) UeRx ^
{ Xcq9*!%o
System.err.println(sMsg); -9S.G
} O ).1>
\bh3&Z'.
JuGQS24
public static void log(int sMsg) *5i~N}
{ $E^#DjhRQ3
System.err.println(sMsg); 4LU'E%vlC
} ZOFBT(oV
} Lp \%-s#5s
Z?%j5G=4w
nI4xK
/* T#lySev
**TestMethod.java Kis\Rg
*/ u1 uu_*
package NetFox; Bx&.Tj
J3sO%4sYR
k3m|I*_\L
public class TestMethod { p6V`b'*>
f77uqv(Y
*it(o
public TestMethod() ];P^q`n=.
{ ///xx/weblogic60b2_win.exe Ih}I`wY-
try{ JH~ve
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Zq|oj^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9?*BN\E5S
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'aB0abr|
fileFetch.start(); o} #nf$v(
} 9Byk/&$U
catch(Exception e){e.printStackTrace ();} Z`xz|:D+
PL8{|Q
~'WvIA (
} ufdC'2cp8
tR5zlm(}
TJ9,c2d+
public static void main(String[] args) _%s_w)
{ B{ NKDkDH
new TestMethod(); FhB^E$r%
} Vgs( feGs
} JF*JFOb
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