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)); 8{d`N|k
} 8-SVgo(
for(int i=0;i<nEndPos.length-1;i++) 1eb1Lvn
{ uHf~KYL
nEndPos = nStartPos[i+1]; p.l]%\QI
} _k j51=
nEndPos[nEndPos.length-1] = nFileLength; crhck'?0
} YDQV,`S7
} {1SxM /
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H=yD}!j
//启动子线程 2%@j<yS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8D+OF 6CM
for(int i=0;i<nStartPos.length;i++) gE$dz#t.
{ pP".?|n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h hdn9n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7.=u:PK7kM
nStartPos,nEndPos,i); Na`qAj}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9~4Kbmr>q
fileSplitterFetch.start(); =DqGm]tA
} {6KU.'#iF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \/,SH?>4x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Qr0GxGWU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sX=!o})0
nEndPos = " + nFileLength); Vxw?"mhP
// fileSplitterFetch[nPos.length-1].start(); -&HN h\
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~fgv7=(!
//等待子线程结束 S-L6KA{
//int count = 0; {1qEN_ERx
//是否结束while循环 {jv1hKTa
boolean breakWhile = false; omY?`(=
5= F-^
hR?rZUl2M
while(!bStop) W]R5\G*
{ x~(Ul\EX
write_nPos(); ,= PDL
Utility.sleep(500); :b ;5O3:B
breakWhile = true; }KOu
E O}(MXS
0xjV*0?s
for(int i=0;i<nStartPos.length;i++) *}0Q S@FN
{ =CJs&Qa2
if(!fileSplitterFetch.bDownOver) Le}q>>o;q
{ Tq?W @DM*
breakWhile = false; +6>Pp[%
break; Kp99y
} ](W#Tj5-
} "5e]-u'
if(breakWhile) G/D{K$=t~
break; x~mXtqg
`q/y|/v<
T<ua0;7
//count++; |g9^]bT
//if(count>4) >0m-S :lk
// siteStop(); !7w-?1?D
} :_^YEm+A
X31kHK5F_
SHaZ-d
System.err.println("文件下载结束！"); ?@u &3/&
} fHgfI@{=j
catch(Exception e){e.printStackTrace ();} K;Xn!:) V:
} QoW3*1o
1"k +K~:
fY `A
//获得文件长度 $~2Ao[
public long getFileSize() Ky=&C8b<
{ a#{a{>
int nFileLength = -1; IEA[]eik>
try{ .!`j3W]
URL url = new URL(siteInfoBean.getSSiteURL()); 7Jqp2\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XYn$yR\dj
httpConnection.setRequestProperty("User-Agent","NetFox"); k82'gJ;MC=
0 Hq$h
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int responseCode=httpConnection.getResponseCode(); *zx;81X=
if(responseCode>=400) Zw3|HV(so
{ ;Rt,"W)
processErrorCode(responseCode); q}8R>`Z{
return -2; //-2 represent access is error z C``G<TB
} $L&*0$[]Q
abK/!m[q
FYi<+]HZ
String sHeader; b1^MX).vH
B>'\g O\2
Rw7Q[I5z%
for(int i=1;;i++) vz_U
{ aJfW75C
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3sL#_@+yz
//Utility.log(in.readLine()); C{,nDa?|
sHeader=httpConnection.getHeaderFieldKey(i); ^WRr "3
if(sHeader!=null) QTDI^ZeuF
{ c1Hv^*Y
if(sHeader.equals("Content-Length")) yK{~
{ }b{N[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .$r(":A#)
break; m3,v&Z
} g6~uf4;
} 5zUD W?
else >Qi2;t~G
break; ;+5eE`]a/L
} ?>w%Lg{L}
} YS/DIH{9e
catch(IOException e){e.printStackTrace ();} dtnAMa5$T
catch(Exception e){e.printStackTrace ();} Ltu;sw
@Pa ;h
S4\T (
Utility.log(nFileLength); .|rpj&>g
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r..Rh9v/=E
return nFileLength; 8 /\rmf\
} \_+d*hHF~
8J@REP4
OW6i2>Or
//保存下载信息（文件指针位置） R[9[lQ'vR
private void write_nPos() 7wZKK0;T
{ h-6kf:XP%
try{ Iz ,C!c
output = new DataOutputStream(new FileOutputStream(tmpFile)); x&kF;UC
output.writeInt(nStartPos.length); Er%nSH^"
for(int i=0;i<nStartPos.length;i++) {>syZZ,h
{ jirxzj
// output.writeLong(nPos); ;ASlsUE\)
output.writeLong(fileSplitterFetch.nStartPos); f>Ij:b`Z2
output.writeLong(fileSplitterFetch.nEndPos); j]jwQRe
} =WHdy;
output.close(); }PoB`H'K5
} JH2d+8O:qK
catch(IOException e){e.printStackTrace ();} RU@`+6j+
catch(Exception e){e.printStackTrace ();} k3u3X~u
} @C?RbTHy
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!x&/M*nBE
//读取保存的下载信息（文件指针位置） -MeGJX:^I
private void read_nPos() yV_aza
{ mhVSZhx|
try{ N U\B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C?X^h{Tp
int nCount = input.readInt(); 6=iz@C7r
nStartPos = new long[nCount]; +1_NB;,e
nEndPos = new long[nCount]; @/7tN3O
for(int i=0;i<nStartPos.length;i++) Lxs
{ EW|bs#l
nStartPos = input.readLong(); =M>pL+#
nEndPos = input.readLong(); `cCsJm$V"
} e![n$/E3R
input.close(); E]i3E[T
} /0@'8f\I
catch(IOException e){e.printStackTrace ();} `gx_+m^
catch(Exception e){e.printStackTrace ();} h#B%'9r
} G D$o|l]\
7"FsW3an
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private void processErrorCode(int nErrorCode) o^}K]ML!t
{ I^emH+!MW
System.err.println("Error Code : " + nErrorCode); u%}zLwMH
} V+(1U|@~
%`?IY<
tDJtsOL
//停止文件下载 9rf6,hF
public void siteStop() @l41'?m
{ s#hIzt
bStop = true; ;=fOyg
for(int i=0;i<nStartPos.length;i++) ]ri5mnB
fileSplitterFetch.splitterStop(); 0Q`Dp;a5&
GHWi,' mr
2<q>]G-nN
} JZ3CCf
} W US[hx,
//负责部分文件的抓取 m<}>'DT
**FileSplitterFetch.java Tr*3:J }
*/ U[,."w]T
package NetFox; 0n<>X&X
]Dec/Nnj
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import java.io.*; ^hiIMqY_{`
import java.net.*; xq$(=WPI
ZRHK?wg'#
zZp0g^;.?
public class FileSplitterFetch extends Thread { Lz6b9W
![1+=F!
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String sURL; //File URL =>3wI'I
long nStartPos; //File Snippet Start Position 1*U)\vK~
long nEndPos; //File Snippet End Position QiKci%=SX
int nThreadID; //Thread's ID 8L1vtYz
boolean bDownOver = false; //Downing is over H?oBax:
boolean bStop = false; //Stop identical 5ir Ffr
FileAccessI fileAccessI = null; //File Access interface v'RpsCov
J,(@1R]KF:
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException A#7/,1h\
{ 00SYNG!
this.sURL = sURL; `)~]3zmG
this.nStartPos = nStart; u:]c
this.nEndPos = nEnd; w :nYsuF
nThreadID = id; R`5g#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Ms=5*_J2Jk
} (fA>@5n
NMs8^O|0
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public void run() MpK3+4UMa
{ )d~{gPr.
while(nStartPos < nEndPos && !bStop) \+M6R<Qw
{ ZWmS6?L.
^/~ZP?%]
Zh
try{ +$}3=n34)
URL url = new URL(sURL); LUs)"ZAi|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &2,3R}B/
httpConnection.setRequestProperty("User-Agent","NetFox"); q@Aw]Kh
String sProperty = "bytes="+nStartPos+"-"; -=cxUDB
httpConnection.setRequestProperty("RANGE",sProperty); X;bHlA-g
Utility.log(sProperty); Kpg?' !I
CM%Rz-c
9r.h^
InputStream input = httpConnection.getInputStream(); @ D,]v:
//logResponseHead(httpConnection); O=[Q>\p
T>hrKn.!D:
c>Tf@Aog>
byte[] b = new byte[1024]; ,&~-Sq)~
int nRead; hpc&s
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?6Wv["%
{ J`]9n>G
nStartPos += fileAccessI.write(b,0,nRead); J@o_-\@
//if(nThreadID == 1) 8NkyT_\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J!Q #xs
} 6:~<L!`&
S{m:Iij[;
}a!ny
Utility.log("Thread " + nThreadID + " is over!"); 0q4PhxR`e
bDownOver = true; ZO!h!2*
//nPos = fileAccessI.write (b,0,nRead); BG6.,'~7o
} ^g|j4N
catch(Exception e){e.printStackTrace ();} s~QIs
} 8J#xB
} ]=o1to-
~470LgpO1
?W_8X2(`
//打印回应的头信息 1N_T/I8_F
public void logResponseHead(HttpURLConnection con) H:EK&$sU
{ Im?/#tX
for(int i=1;;i++) Egz6rRCvg
{ $Zr \$z2
String header=con.getHeaderFieldKey(i); |}2/:f#Iz*
if(header!=null) ?0'e_s
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /6rQ.+|).
Utility.log(header+" : "+con.getHeaderField(header)); >k ==7#P
else %"cOX
break; F Uz1P
} JMk2OK{0
} ,SPgop'
V?Q45t Ae
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public void splitterStop() x ;~;Ah.p
{ zB`J+r;LU
bStop = true; +PnuWK$
} Wy\^}
*o5[P\'6
(-Q~@Q1
} w_V A:]j4
{Mj- $G"
8bQXC+bK
/* {\`y)k 7
**FileAccess.java #eN2{G=4+
*//文件访问(定位，写) AOkG.u-k
package NetFox; }z#M!~
import java.io.*; C:t?HLY)fG
*P5\T4!+d
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public class FileAccessI implements Serializable{ YcV^Fqi!
*DvX||`&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 r*8a!jm?
RandomAccessFile oSavedFile; x4PzP
long nPos; $a8,C\me?
ZXL'R|?
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public FileAccessI() throws IOException XZ{rKf2
{ vNs`UkA
this("",0); <KK.f9^o(
} ?-%(K^y4r
r73W.&
r~JGs?GH
public FileAccessI(String sName,long nPos) throws IOException n_rpT.[
{ =-~))!(
oSavedFile = new RandomAccessFile(sName,"rw"); l53Q"ajG
this.nPos = nPos; si)>:e
oSavedFile.seek(nPos); SUIJ{!F/
} sV-PR]
>&:}L%
I^( pZ9
public synchronized int write(byte[] b,int nStart,int nLen) F-b]>3r
{ _&\'Va$
int n = -1; ?%su?L
try{ UCjx
oSavedFile.write(b,nStart,nLen); SPRTJdaC9
n = nLen; K?[Vz[-Fc
} Hc@_@G
catch(IOException e) !hM`Oe`S
{ ,`Z4fz:
e.printStackTrace (); R&6@*Nn
} )+'=Zvgej=
t:V._@
rv(N0p/
return n; q2J|koT
} +jZa A/
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} +ctU7 rVy
gm,AH85
~XP|dn}
/* nyqX\m-
**SiteInfoBean.java 0SWqC@AR%
*/ *xpn-hCp<
package NetFox; MZX)znO
.%7Le|Fb"
; U7P{e05
public class SiteInfoBean { T?f{.a)
Xe_djy'8
f OR9N/
private String sSiteURL; //Site's URL gJuK%P
private String sFilePath; //Saved File's Path T30fp
private String sFileName; //Saved File's Name "= %"@"<)
private int nSplitter; //Count of Splited Downloading File M^8zqAA
|>xuH#Q
"0Z/|&
public SiteInfoBean() E9I08AODS
{//nSplitter的缺省值为5 Ns1n|^9
//default value of nSplitter is 5 0M&n3s{5I
this("","","",5); f42F@M(:
} HBvyX`-
Z}0xK6
c%hXj#;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R31Z(vY
{ M_UmnqN1C
sSiteURL= sURL; o938!jML_
sFilePath = sPath; <EgJm`V
sFileName = sName; "&f|<g5
this.nSplitter = nSpiltter; ,q#SAZ/N
WHv6E!^\_
`5h^!="
} 0{B<A^Bf
%5zIh[!1$
i}C%8}%
public String getSSiteURL() wGT>Xh!
{ b:~#;$g
return sSiteURL; O.QR1
} [sk n9$
Zqe$S +u
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public void setSSiteURL(String value) F."ZCEb
{ tw<Oy^i
sSiteURL = value; T6\]*mlr
} xFThs,w
^swj!da
9)S3{i6w
public String getSFilePath() W$,/hB& z
{ 9Xa.%vw>
return sFilePath; _oG%bNM
} c u";rnj
_6h.<BR
?0KIM* .
public void setSFilePath(String value) t>N2K-8Qh
{ G}l9 [lE
sFilePath = value; zY*~2|q,s
} $)KODI>|
XY? Cl
PIo@B|W-SX
public String getSFileName() nu1XT 1q1
{ ']\SX*z?
return sFileName; T*#M'H7LSQ
} 4\|Q;@f
xq,ql@7
<Rn-B).3bs
public void setSFileName(String value) Dbi ^%
{ H}G 9gi
sFileName = value; O"o|8 l}M/
} }vY^eOK.
-u"|{5? '
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public int getNSplitter() D~i5E9s5
{ |X XO0
return nSplitter; U" 3L
} XMZ$AeF@
gSwHPm%zn
C:^ :^y
public void setNSplitter(int nCount) [$d]U.
{ LQ%QFfC
nSplitter = nCount; k1yqerA
} }m^^6h
} v_U/0 0
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( [a$Z2m
/* VCnf`wZB"
**Utility.java <zTz/Hk`
*/ kxEq_FX
package NetFox; ;3& wO~lW
`DSFaBj,
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public class Utility { Z{l`X#':
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kRwY#
public Utility() GoX<d{
{ 1uKIO{d@
$39TP@?:Z)
*>[q*SF
} @m%B>X28F
V(LfFO{^>?
//线程睡眠 Y^d#8^cP
public static void sleep(int nSecond) n.NWS/v_{
{ Syl9j]
try{ ABp8PD
Thread.sleep(nSecond); jG& 8`*|*
} Jc5YGj7
catch(Exception e) L_:~{jV
{ "^{Hta
e.printStackTrace (); 7tJ#0to
} C-,#t5eir
} KkzG#'I1
*'M+oi
//日志 w&es N$2
public static void log(String sMsg) mrKIiaU<J
{ &jg>X+;
System.err.println(sMsg); 5oB#{h
} |7Z}#eP//
wM;=^br
q`z1ht nf
public static void log(int sMsg) 9X#]Lg?b
{ >XuPg(Ow
System.err.println(sMsg); m`xYd
} tOk=m'aUK
} I'n}6D.M
=mcQe^M
"9*MSsU
/* EUgKJ=jw
**TestMethod.java /Gb)BJk!
*/ &h6 `hP_
package NetFox; UIIsgNca
B'vIL'
|vG?H#y
public class TestMethod { ^ rO}'~(
R Eo{E
mQU t 'j4
public TestMethod() jzi^OI7
{ ///xx/weblogic60b2_win.exe ,]9p&xu
try{ s{Y-Vdx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qI74a F
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Lke!VS!P&
SiteFileFetch fileFetch = new SiteFileFetch(bean); fp3`O9+em
fileFetch.start(); ose)\rM'
} :8+x&zn
catch(Exception e){e.printStackTrace ();} (Nf!E[}Z
W ,]Ua]
s!F8<:FRJD
} 4~nf~
Z{F^qwne
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public static void main(String[] args) K\lu;
{ i~4$V
new TestMethod(); !\Xrl) $j{
} CX5>/
} Ycxv=Et
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