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)); Ekm7 )d$
} 6V+ qnUk
for(int i=0;i<nEndPos.length-1;i++) nCvPB/-
{ ]43bere
nEndPos = nStartPos[i+1]; (5Tvsw`
} V'2EPYB
nEndPos[nEndPos.length-1] = nFileLength; +1Ph<zq"
} Lx U={Y0
} X#UMIlU
wj|x:YZ*
>7U>Yh
//启动子线程 j#6|V]l
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; p'?w2YN/
for(int i=0;i<nStartPos.length;i++) oXt,e
{ >Dg#9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =`C4qC_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DV]7.Bm
nStartPos,nEndPos,i); A?"h@-~2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UU}7U]9u
fileSplitterFetch.start(); .`Zf}[5[
} <;t)6:N\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r\9TMg`C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ftavbNR`W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n1:v HBM@\
nEndPos = " + nFileLength); -,":5V26
// fileSplitterFetch[nPos.length-1].start(); ]y)Q!J )Q
baoD(0d
]`w}+B'/
//等待子线程结束 dd7 =)XT+
//int count = 0; 2#/p|$;Ec'
//是否结束while循环 2$zU&p7sV
boolean breakWhile = false; YY4-bNj[p
b}zBn8l
9<]a!:!^
while(!bStop) >^"BEG9i:
{ {-63/z
write_nPos(); M\+*P,i
Utility.sleep(500); 8xI`jE"1
breakWhile = true; W)SjQp6
Hwe)Tsh e
s3lwu :4f
for(int i=0;i<nStartPos.length;i++) @#b0T:+v'
{ =ziy`#fm,
if(!fileSplitterFetch.bDownOver) *R`MMm
{ PG)_L.7rJ
breakWhile = false; a~^Srj!}x
break; =O{~Q3z@s
} X`\:_|
} 9g?xlue#?
if(breakWhile) %W|DJ\l8"
break; %bX0 mN
"t&{yBQ0u
R/<=mZ
//count++; $)e:8jS=
//if(count>4) td(M#a-
// siteStop(); 0%)5.=6
} VZA3IbK}
BSp$F WvT?
h<[+HsI
System.err.println("文件下载结束！"); `:-J+<`
} n*qN29sx
catch(Exception e){e.printStackTrace ();} j[S`^2
} >4![&&
>3 Ko.3&
|r~ uos
//获得文件长度 iM64,wnA
public long getFileSize() bGh0<r7R
{ %7`d/dgR
int nFileLength = -1; Wm6dQQ;Bj
try{ )hL^+Nn bR
URL url = new URL(siteInfoBean.getSSiteURL()); ^w6eWzI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5urE
httpConnection.setRequestProperty("User-Agent","NetFox"); Y%vP#>h
2Yyb#Ow
U %:c],Fk
int responseCode=httpConnection.getResponseCode(); Z[,`"}}hv=
if(responseCode>=400) 135Par5v
{ U \Dca&=
processErrorCode(responseCode); z=?0)e(H,
return -2; //-2 represent access is error 'rV2Bt,
} 6hbEO-(
C"T,MH
'}O!2W&Y]%
String sHeader; 8SD}nFQ
=O^7TrM
R/N<0!HZ
for(int i=1;;i++) 8 G?b.NE^
{ V}`M<A6:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *t=i
//Utility.log(in.readLine()); '=%i,
sHeader=httpConnection.getHeaderFieldKey(i); 7L{li-crI
if(sHeader!=null) p6blD-v
{ \3 KfD'L
if(sHeader.equals("Content-Length")) 2v|qLfe1
{ rZ866\0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s}b*5@8|tA
break; 4ROWz
} [n<.fw8$b
} )b9I@)C
else '{D%\w5{
break; @c"yAy^t
} h2}am:%mC
} *7vue"I*Z
catch(IOException e){e.printStackTrace ();} ^X;JT=r
catch(Exception e){e.printStackTrace ();} U3q5^{0d/
`Wwh`]#"~d
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Utility.log(nFileLength); u@"o[e':
'O1.6*K
)n7)}xy#z
return nFileLength; 'o8\`\'H!
} n^Au*'
7dhn'TW
xXa#J)'
//保存下载信息（文件指针位置） #HcI4j:s!
private void write_nPos() )9pBu B
{ Y_shy6"KH
try{ }I<N^j=/pO
output = new DataOutputStream(new FileOutputStream(tmpFile)); H5^Y->
output.writeInt(nStartPos.length); vj@V !j?
for(int i=0;i<nStartPos.length;i++) F0: &>'}
{ i0&) N,5_
// output.writeLong(nPos); %~(~W>^A
output.writeLong(fileSplitterFetch.nStartPos); n1`T#%e
output.writeLong(fileSplitterFetch.nEndPos); IgiqFV{
} AuM:2N2
output.close(); lvig>0:M
} G\IocZ3Gz
catch(IOException e){e.printStackTrace ();} p d%LL?O
catch(Exception e){e.printStackTrace ();} ht$ WF
} D1~^\)*
3\9][S-B
pgfu+K7?w
//读取保存的下载信息（文件指针位置） "]9_Fv
private void read_nPos() D99N#36PU
{ Bzm.X=U:
try{ 8I {56$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9w$7VW;
int nCount = input.readInt(); Ty iU1,oO
nStartPos = new long[nCount]; [EcV\.
nEndPos = new long[nCount]; 4jD\]Q="1
for(int i=0;i<nStartPos.length;i++) mc56L[
{ \Em-.%c
nStartPos = input.readLong(); DwC@"i.
nEndPos = input.readLong(); iqlVlm>E
} IM|Se4;x
input.close(); nvwDx*[qN
} 8ST~$!z$
catch(IOException e){e.printStackTrace ();} |7Yvq%E
catch(Exception e){e.printStackTrace ();} {)jk_&c7
} }W)Mwu'W
_/8y1)I
.k|-Ks|d|
private void processErrorCode(int nErrorCode) jS}'cm-
{ aliQ6_
System.err.println("Error Code : " + nErrorCode); FL~9</
} !}C4{Bgt*
="=#5C
aSxG|OkKy
//停止文件下载 Ny[s+2?
public void siteStop() 3Y=,r!F.h
{ (#lm#?<)
bStop = true; L)=8mF.
for(int i=0;i<nStartPos.length;i++) %!#rrt,F
fileSplitterFetch.splitterStop(); Ld'EABM
u<J2p?`\&`
QDl)92z
} ge@reGfsB1
} GZ}*r{
//负责部分文件的抓取 vJzxPy|
**FileSplitterFetch.java G-ZrM
*/ [cY?!Qd0
package NetFox; T\.7f~3
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import java.io.*; RbyF#[}
import java.net.*; |^\Hv5
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t PAt?
public class FileSplitterFetch extends Thread { Fj36K6!#?
k^~@9F5k
p}cd}@cQ6
String sURL; //File URL kz3?j<
long nStartPos; //File Snippet Start Position [k}dES#
long nEndPos; //File Snippet End Position ktdz@f
int nThreadID; //Thread's ID ,$ho2R),Fn
boolean bDownOver = false; //Downing is over MJpP!a^Q
boolean bStop = false; //Stop identical ye56-T
FileAccessI fileAccessI = null; //File Access interface O>kXysMv>
:tg@HyY)
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException P<TpG0~(
{ V%VrAi.
this.sURL = sURL; 8-W"4)@b
this.nStartPos = nStart; Q;d+]xj
this.nEndPos = nEnd; H,01o5J
nThreadID = id; j P{:A9T\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]wJ}-#Kx
} ZJ)3GF}4
`S uS)RhA)
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public void run() 8b8e^\l(
{ {-:4O\/
while(nStartPos < nEndPos && !bStop) wi![0IE )
{ [w+yQ7P
9;r48)5
u)N2
try{ ptnMCF
URL url = new URL(sURL); sj?`7kg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /7!_un9
httpConnection.setRequestProperty("User-Agent","NetFox"); >;T$#LZ
String sProperty = "bytes="+nStartPos+"-"; "P>$=X~Zi
httpConnection.setRequestProperty("RANGE",sProperty); Ew)n~!s
Utility.log(sProperty); ,'/HcF?yf
IF,i^,
?HEo9/ *7
InputStream input = httpConnection.getInputStream(); '2Mjz6mBDA
//logResponseHead(httpConnection); #3 }5cC8_
({ :yw
.YnP%X=
byte[] b = new byte[1024]; ~5XL@jI^
int nRead; 8YT_DM5iI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .x\/XlM
{ 2^k^"<h5j
nStartPos += fileAccessI.write(b,0,nRead); Dohl,d
//if(nThreadID == 1) jpPdjQ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {7j6$.7J$&
} 3N)Ycf8
/*mFP.en
~_/<PIm
Utility.log("Thread " + nThreadID + " is over!"); \Nh^Ig
bDownOver = true; D]LFX/hlH
//nPos = fileAccessI.write (b,0,nRead); o|Yn(xu-
} E.WNykF-
catch(Exception e){e.printStackTrace ();} 9Y!0>&o
} DkF@XK0c3
} Wme1Uid
)U"D4j*p
{d*qlztO
//打印回应的头信息 ~(*co[_
public void logResponseHead(HttpURLConnection con) 6qmo ZAg
{ E#&c]9QM75
for(int i=1;;i++) 4F1.D9u
{ TYmUPS$
String header=con.getHeaderFieldKey(i); f0N)N}y
if(header!=null) Q KDb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c)n0D=
Utility.log(header+" : "+con.getHeaderField(header)); 6@,'m
else 0&SrKn
break; r7wx?{~ 28
} wXIe5
} hr$VVbOho
;c \zgs~"T
D!OG307P
public void splitterStop() +lk\oj$S+
{ inq4CGY
bStop = true; 4P-'(4I)
} m,"cbJ /
nf+"vr}1
+Y>cBSO
} ,]>`guDV
Sx4UaV~"
k7Be'E BKG
/* It!.*wp
**FileAccess.java =km-`}I,
*//文件访问(定位，写) 1z$}*`
package NetFox; u\Erta`
import java.io.*; 2+r)VF:
EnsNO_"e|
)sz2 9
public class FileAccessI implements Serializable{ ~[ ks|
Cs~\FI1wR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =^%Pwkz
RandomAccessFile oSavedFile; hjm.Ath
long nPos; (Db*.kd8,
VUg~[
d9Ow 2KrC
public FileAccessI() throws IOException !_/8!95
{ y1jGf83
this("",0); t"Vr;0!{
} EL)/5-=S
l52n/w#qFB
<EMLiiNY
public FileAccessI(String sName,long nPos) throws IOException ?'8MI|*l%
{ #mz,HK0|aC
oSavedFile = new RandomAccessFile(sName,"rw"); Ws}kb@5
this.nPos = nPos; q[,R%6&'
oSavedFile.seek(nPos); f4\p1MYQ
} #uRq] 'P
l7r N
]@j"0F/`
public synchronized int write(byte[] b,int nStart,int nLen) =[tls^
{ QWQ6j#`
int n = -1; X0r#,u
try{ lLwQridFXh
oSavedFile.write(b,nStart,nLen); \`iW__
n = nLen; r+W8m?oi
} 9rvxp;
catch(IOException e) KohQ6q
{ 5yN8%_)T
e.printStackTrace (); eABdye
} Xy(SzJ%
aK=3`q
4`'BaUU(
return n; %`uRUex
} V2sB[Mw
k`J..f9
\kJt@ [w%
} 3M:B?2
3S2p:\]
VA&OI;=ri
/* Ok{:QA~#
**SiteInfoBean.java _F$t#.o
*/ +\(ay"+ d
package NetFox; s)'_{ A"h
kjKpzdbD
JgjL$n;F
public class SiteInfoBean { dmMr8-w
#*aGzF
tH|Q4C
private String sSiteURL; //Site's URL A ** M"T
private String sFilePath; //Saved File's Path <cS7L0h
private String sFileName; //Saved File's Name oB}G^t
private int nSplitter; //Count of Splited Downloading File Rb>RjHo S
%JH_Nw.P
sN`o_q{Q
public SiteInfoBean() ';T5[l,
{//nSplitter的缺省值为5 ]TZWFL-
//default value of nSplitter is 5 u:u 7|\q
this("","","",5); GbrPtu2{@V
} M[3w EX^
D"XQ!1B%
?%fZvpn-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 87E3pe
{ 3usA
sSiteURL= sURL; z&J ow/
sFilePath = sPath; :W<,iqSCm
sFileName = sName; WHj4#v(
this.nSplitter = nSpiltter; C-b%PgA
~ z&A
E#F9<=mA)
} H5MAN,`
58ZiCvqv
i}{Q\#=#
public String getSSiteURL() W[Ew6)1T
{ AT'$VCYC(
return sSiteURL; +jZg%$Q!#
} N#!1@!2BN
9^*YYK}%
='||BxB
public void setSSiteURL(String value) A VG`r2T
{ v.&*z48
sSiteURL = value; }eRG$)'
} kvVz-PJy
rQ@o
nZ+5@( *
public String getSFilePath() Zgf||,
{ bRe*(
return sFilePath; Saq>o.
} v?"ee&Y6
EKJ4_kkjM
c5+lm}R?
public void setSFilePath(String value) yacGJz^f=
{ MxA'T(Ay
sFilePath = value; W]MJ!4
} qvT+d l3#[
mSw?iL
9nAK6$/
public String getSFileName() QN8Hz/}\
{ 5va&N<U
return sFileName; gJ~*rWBK:
} U$J_:~
s31_3?Vdf,
4zDAfi#0
public void setSFileName(String value) ;m:GUp^[
{ 8VGXw;(Y,d
sFileName = value; Zd/~ *ZA
} &Zy=vk*
;4#8#;
k3h53QTmC
public int getNSplitter() &{{f|o=u.
{ eZkz 1j~
return nSplitter; BQ)43Rr>
} [ +@<T)
Lk+1r8
\I{A33i2w
public void setNSplitter(int nCount) aT1W]i
{ BFu9KS+@)
nSplitter = nCount; a8P6-)W
} CP#MNNvgrw
} R*#Q=_
;//qjo
W/X;|m`
/* T0)y5
**Utility.java ? NK}q\$
*/ fT~<C {
package NetFox; )F2tV ]k\
`3s-\>
6_><W"r:]
public class Utility { \uIC<#o"N
5i&V ~G
rmoEc]kt]
public Utility() ^Exq=oV
{ e(N <Mf
u`nn{C4D"
Zul32]1r
} l@jJJ)Qyk
.HJHJ.Js8X
//线程睡眠 B\w`)c
public static void sleep(int nSecond) DQQjx>CK
{ IKpx~
try{ FeRuZww._J
Thread.sleep(nSecond); BJrNbo;T
} +'4dP#
catch(Exception e) d0,F'?.0|
{ )q-!5^ak
e.printStackTrace (); jd'R2e
} bv];Gk*Z-
} >p:fWQ6
h"S/D[
//日志 .H.v c_/
public static void log(String sMsg) ^:j:;\;
{ <p .[E]a2_
System.err.println(sMsg); g5\B-3{
} \H12~=p`B
en":
8RD)yRJ
public static void log(int sMsg) pU/.|Sh
{ 4w[ta?&6B
System.err.println(sMsg); A+8b]t_k
} ~'mhC46d
} LvdMx]*SSr
@h3)!#\N
[AwE
/* c:TP7"vG
**TestMethod.java !IU*Ayg
*/ DR=1';63
package NetFox; 6*Qpq7Ml
xb>+~59:
yp/*@8%_E
public class TestMethod { Rw%KEUDm
z<*]h^!3
'M/&bu r
public TestMethod() >fQN"(tf
{ ///xx/weblogic60b2_win.exe fXj
try{ {}e IpK,+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); AG2jl/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c5pG?jr+d
SiteFileFetch fileFetch = new SiteFileFetch(bean); w:v:znQrW
fileFetch.start(); .ji%%f
} j=4>In?x
catch(Exception e){e.printStackTrace ();} ,Fiiw
sJ=B:3jS0
{D< ?.'
} wl9icrR>
"Xc=<rX
Bw[VK7
public static void main(String[] args) H;ib3?
{ 6 H.Da]hk
new TestMethod(); y 6<tV.
} 9m4|1)
} #u^d3 $Nj
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