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)); TqS2!/jp
} )ZT6:)
for(int i=0;i<nEndPos.length-1;i++) DNm(:%)0
{ ZhhI@_sz
nEndPos = nStartPos[i+1]; BCBEX&0hk{
} ;\<""Yj@l
nEndPos[nEndPos.length-1] = nFileLength; OZ(Dpx(Q
} SQh+5
} y]yine
I*^5'N'
XOu+&wOu
//启动子线程 H"#)&a7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AI&qU/}
for(int i=0;i<nStartPos.length;i++) GxYW4b
{ @)o0GHNP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "Z;~Y=hC13
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), w?kGi>7E
nStartPos,nEndPos,i); L<bYRGz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wu4ot0SZ
fileSplitterFetch.start(); ]kRI}Om2
} :~vxZ*a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~V @;(_T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <v]z6B@9!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7e1dEgn
nEndPos = " + nFileLength); T |37#*c
// fileSplitterFetch[nPos.length-1].start(); -7k[Vg?
C`dkD0_
a*D,*C5}
//等待子线程结束 G;/Q>V
//int count = 0; w'A tf
//是否结束while循环 <O.Kqk* nq
boolean breakWhile = false; N*Yy&[
os[ZIHph
W$r^
while(!bStop) RL6Vkd?
{ G%S6$@:
write_nPos(); PkTfJQP8
Utility.sleep(500); cg,Ua!c
breakWhile = true; ZP-dW|<[x
}g>kpa0c
lK*jhW?3:
for(int i=0;i<nStartPos.length;i++) S`=n&'
{ 6JSY56v
if(!fileSplitterFetch.bDownOver) (VyA6a8
{ b4CF`BG
breakWhile = false; )Ob]T{GY
break; H8&p<=
} \ZMP_UU(
} j9:/RJS
if(breakWhile) 1SUzzlRx
break; X]!D;7^
)|pU.K9qZ
/Pk:4,
//count++; LKx`v90p
//if(count>4) r!kLV)_
// siteStop(); :=9<
} oSY7IIf%L
K\(6rS}N
}Gr&w-v
System.err.println("文件下载结束！"); P`EgA
} 0Gsu
catch(Exception e){e.printStackTrace ();} Jt]&;0zn2
} H@D;e
hsz^rZ
e[{mVhg4E
//获得文件长度 .*Vkua
public long getFileSize() !^iwQ55e2A
{ `*aBRwvK~
int nFileLength = -1; &s8<6P7
try{ g*y/j]
URL url = new URL(siteInfoBean.getSSiteURL()); K(VW%hV1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tuLH}tkNY
httpConnection.setRequestProperty("User-Agent","NetFox"); ARF\fF|<2
qSTWb%
vk'rA{x
int responseCode=httpConnection.getResponseCode(); c<4F4k7
if(responseCode>=400) l^W uS|G[
{ ] 8Tzr
processErrorCode(responseCode); mI"D(bx\
return -2; //-2 represent access is error AbfZ++aJ
} =K(JqSw+M
Vb!O8xV4;+
fu R2S70d
String sHeader; TSjIz5
.'T40=7
X>zlb$
for(int i=1;;i++) +sf .PSz$
{ ]Blf9h7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zvO:"w}
//Utility.log(in.readLine()); iZxt/}1X0
sHeader=httpConnection.getHeaderFieldKey(i); 8lP6-VA
if(sHeader!=null) BzN@gQo
{ #U ASH&
if(sHeader.equals("Content-Length")) U~H?4Izl=
{ 66\jV6eH7L
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); cyQBqG
break; Lm6**v
} ->gZ)?Fqy
} <)U4Xz?
else 3t"4TjAy
break; _<*Hv*Zm
} 6F|j(LB
} `A)"%~
catch(IOException e){e.printStackTrace ();} *Y6xvib9*
catch(Exception e){e.printStackTrace ();} u0 y 1
Zu/<NC (
\/5RL@X}
Utility.log(nFileLength); [6tSYUZs
gl7|H&&xV
%J~WC$=Qv
return nFileLength; qCPmbg
} :50b8
t ls60h
L{&U V0q!
//保存下载信息（文件指针位置） N#ioJ^}n:
private void write_nPos() '@=PGpRF
{ u2iXJmM*
try{ xDLG=A%]z
output = new DataOutputStream(new FileOutputStream(tmpFile)); Vba.uKNjk
output.writeInt(nStartPos.length); !{%&=tIZ
for(int i=0;i<nStartPos.length;i++) I#rubAl
{ e0HfP v_
// output.writeLong(nPos); 'LSz f/w
output.writeLong(fileSplitterFetch.nStartPos); j/!H$0PN
output.writeLong(fileSplitterFetch.nEndPos); y~ rXl
} ]$b2a&r9
output.close(); 3n;K!L%zMT
} #& ?g %'
catch(IOException e){e.printStackTrace ();} s60 TxB
catch(Exception e){e.printStackTrace ();} kG0Yh2;#
} |> enp>
s1j{x&OSq
* ?Jz2[B
//读取保存的下载信息（文件指针位置） ^Q}eatEn
private void read_nPos() f 2YLk
{ &[[K"aM1
try{ $ &UZy|9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &qM[g9
int nCount = input.readInt(); ci9R.U)
nStartPos = new long[nCount]; EcL-V>U#M
nEndPos = new long[nCount]; rNDrp@A>
for(int i=0;i<nStartPos.length;i++) p9eRZVy/
{ U9hS<}<Ki
nStartPos = input.readLong(); k@mVxnC
nEndPos = input.readLong(); eD?3"!c!
} Vr.Y/3N&'
input.close(); ;q>9W,jy
} V@-)\RZm
catch(IOException e){e.printStackTrace ();} f. }c7
catch(Exception e){e.printStackTrace ();} <If35Z)~
} xg@NQI@7
#KlCZ~s
"2ru7Y"
private void processErrorCode(int nErrorCode) c3%@Wj:fo
{ !^c@shLN4
System.err.println("Error Code : " + nErrorCode); 8jlLUG:g
} ~nLN`Hd
ZJW[?V\5=
5&Ts7& .
//停止文件下载 bpAv1udX-W
public void siteStop() FDzqL;I
{ h&&6r\4/|
bStop = true; I{'f|+1
for(int i=0;i<nStartPos.length;i++) oPf)be| #
fileSplitterFetch.splitterStop(); PUJ2`iP1^3
pmvT$;7I
4bVO9aUG{
} jhgX{xc
} J5Z%ImiT^O
//负责部分文件的抓取 g^Yl TB
**FileSplitterFetch.java `O?T.p)
*/ +avMX&%
package NetFox; 2NGeC0=
ji1HV1S
~+X9g
import java.io.*; e!-,PU9+
import java.net.*; +gd2|`#
{]*x*aa\
AFvgbn8Qh
public class FileSplitterFetch extends Thread { (:V>Hjt
2zSG&",2D
^g1f X1
String sURL; //File URL R:-JkV>e:
long nStartPos; //File Snippet Start Position +yob)%
long nEndPos; //File Snippet End Position gU^$Sx7'
int nThreadID; //Thread's ID MB ju![n
boolean bDownOver = false; //Downing is over OI1ud/>h
boolean bStop = false; //Stop identical cLa]D[H
FileAccessI fileAccessI = null; //File Access interface KOq;jH{$
!rDdd%Z
7M_U2cd|TD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +6$g!S5{
{ :AdDLpk3j
this.sURL = sURL; XKA&XpF
this.nStartPos = nStart; 7\zZpPDV
this.nEndPos = nEnd; ]r!>{
nThreadID = id; F;ZSzWq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 o;a:Dd
} 'TC/vnM
}eQRN<}P
.o1^Oh
public void run() ,B(7\
{ OJN2z
while(nStartPos < nEndPos && !bStop) 9Etz:?)b
{ W6T|iZoV"r
.#u_#=g?
8[CB>-9
try{ s5.AW8X=?*
URL url = new URL(sURL); SVlua@]ChU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )D'^3)FF
httpConnection.setRequestProperty("User-Agent","NetFox"); o@]So(9f
String sProperty = "bytes="+nStartPos+"-"; +;g{$da5
httpConnection.setRequestProperty("RANGE",sProperty); |6UtW{2I/
Utility.log(sProperty); FlfI9mm
fJ\sguZ
]eQV,Vt
InputStream input = httpConnection.getInputStream(); IEjP<pLe
//logResponseHead(httpConnection); J89Dull
G2LK]
""Zp:8o
byte[] b = new byte[1024]; '\~$dtI$
int nRead; >-_d CNZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,uw132<b
{ y-p70.'{U
nStartPos += fileAccessI.write(b,0,nRead); +_v$!@L8
//if(nThreadID == 1) g-`~eG28D5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #po5_dE\*
} g~7Ri-"
}>^Q'BW;65
Q%/<ZC.Mz6
Utility.log("Thread " + nThreadID + " is over!"); EM7+VO(
bDownOver = true; J$4wL F3
//nPos = fileAccessI.write (b,0,nRead); n .!Ym X4
} /vY_Y3k#
catch(Exception e){e.printStackTrace ();} aK,z}l(N
} 6:U$w7P0 e
} YY?a>j."a
_|72r}j
0JgL2ayIVI
//打印回应的头信息 "dR|[a<#g
public void logResponseHead(HttpURLConnection con) 2j(h+?N7k
{ >FhK#*Pa
for(int i=1;;i++) J};z85B
{ hjO*~
String header=con.getHeaderFieldKey(i); `X,yM-(
if(header!=null) &U+ _ -Ph
//responseHeaders.put(header,httpConnection.getHeaderField(header)); TI9UXa:V\
Utility.log(header+" : "+con.getHeaderField(header)); V`adWXu
else MYBx&]!\
break; ut>4U'.H
} =#mTfJ
} 0Io'bF
#j@71]GI
UgWs{y2SE.
public void splitterStop() Ladsw
{ f84:hXo6
bStop = true; )CX4kPj
} \#68;)+=
"x@='>:$
J$~<V IX
} &a/__c/l
5Z4-Z
>3awn*N
/* ^kST
**FileAccess.java y=Mq(c:'UN
*//文件访问(定位，写) `mye}L2I
package NetFox; 0l;<5
import java.io.*; kNu'AT#3|
q1E:l!2al
) 'j:
public class FileAccessI implements Serializable{ R),zl_d_
IrMl:+t\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x{NX8lN
RandomAccessFile oSavedFile; UpXz&k
long nPos; \c[IbL07
86f2'o+
U/lM\3v/e
public FileAccessI() throws IOException ;n\= R 5.
{ B3Jgd,[
this("",0); fQLt=Lrp
} [FUjnI
[![%9'+P
S4witIK5
public FileAccessI(String sName,long nPos) throws IOException LQnkcV
{ Sx
oSavedFile = new RandomAccessFile(sName,"rw"); iTW? W\d
this.nPos = nPos; /~4"No@
oSavedFile.seek(nPos); ~x{.jn
} 0J.dG/I%
~)?
n;R#,!<P
public synchronized int write(byte[] b,int nStart,int nLen) :Q+5,v-c
{ iut`7
int n = -1; >=iy2~Fz,
try{ 4/X/>Y1
oSavedFile.write(b,nStart,nLen); k`".
n = nLen; c`x7u}C
} q P ;A}C
catch(IOException e) @DW[Z`X
{ 4h6k`ie!$
e.printStackTrace (); RvJ['(-
} 5-)#f?
+7Kyyu)y@
B7\k< Nit0
return n; tU"raP^=
} lCW8<g^
bYe;b><G
HaA1z}?n
} R];Oxe
s=?aox7
yV)m"j
/* 4YZS"K'E
**SiteInfoBean.java 93[DAs
*/ X5YiFLH>y\
package NetFox; Qy#)Gxp
8\<jyJ
]E3U J!!
public class SiteInfoBean { OT %nrzP
=TR,~8Z|
DaNW~rd{
private String sSiteURL; //Site's URL I[o*RKT'"
private String sFilePath; //Saved File's Path A5#y?Aq
private String sFileName; //Saved File's Name _eLWQ|6Fx
private int nSplitter; //Count of Splited Downloading File PIcrA2ll
(_* wt]"'
Ct$82J
public SiteInfoBean() `Lyq[zg8
{//nSplitter的缺省值为5 ;%J5=f%z)
//default value of nSplitter is 5 /Tz85 [%6
this("","","",5); O?bK%P]ay
} N132sN2
X7UBopm&
us?&:L|!=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;??ohA"{5
{ %;`>`j5
sSiteURL= sURL; Z.&\=qiY
sFilePath = sPath; g1DmV,W-Q
sFileName = sName; `=tyN@VC
this.nSplitter = nSpiltter; ,KW;2t*IQ@
Vu0KtG9
]kktoP|D
} toa-Wa{
eN0P9.eqM
[nN7qG
public String getSSiteURL() LR)& [{Kk
{ 'TN)Lb*
return sSiteURL; O^{1RV3:,T
} n1(?|aJ#1
M\/XP| 7
p|6v~
public void setSSiteURL(String value) cErI%v}v0
{ aP~gaSx
sSiteURL = value; kL{;.WsB
} vg%QXaM
#Olg(:\
kv|,b
public String getSFilePath() _45cH{$sA
{ ;cP8?U
return sFilePath; ft5DU/%
} #JNy
3VCqp13
oC dGQ7G}
public void setSFilePath(String value) DMgBcP
{ vx0UoKX
sFilePath = value; MB$a82bY
} Zy$Lrr!
&/F_*=VE
P;foK)AM
public String getSFileName() (}H ,ng'4
{ VZxTx0: ,
return sFileName; mVf.sA8
} hYt7kq!"
FUTn
")\aJ8
public void setSFileName(String value) ]S/G\z
{ l:e9y$_)
sFileName = value; ?iSGH'[u
} A!HK~yk~Q
?z.Isvn
!'c|N9
public int getNSplitter() XeUprN
{ iz x[
return nSplitter; CyTFb$Z
} b~wKF0vq
!RMS+Mm?
vo;5f[>4i
public void setNSplitter(int nCount) z-Hkz
{ # cWHDRLX
nSplitter = nCount; I)[B9rbe
} Baq ~}B<
} zzJ^x8#R
9eSRCLhgD
n&7@@@cA
/* O)<r>vqe}
**Utility.java [t}):}~F|
*/ nZW4}~0j
package NetFox; @,6ST0xT (
cyc>_$/;1
b+$o4l/x
public class Utility { !$E~\uT
'wE\{1~_[+
`i4I!E
public Utility() \(9p&"Q-
{ 6aSM*S)
=tq7z =k
fv|%Ocm
} ScHlfk p
o}!&y?mp
//线程睡眠 >Jiij
public static void sleep(int nSecond) #Y: ~UVV
{ ;qG1r@o
try{ 7 s-`QdWX
Thread.sleep(nSecond); yTj p-
} 8!6<p[_
catch(Exception e) wLSjXpP8
{ g`{Dxb,t
e.printStackTrace (); r&/D~g\"|[
} o@@_J@}#
} 5~-}}F
s#`cX0L)
//日志 CH#kvR2
public static void log(String sMsg) wK ][qZ ]
{ m^Rd Iy)
System.err.println(sMsg); kFnUJM$r
} gm}C\q9
_we3jzMW
B~BUWWMfp
public static void log(int sMsg) |y'b217t
{ 2}>go^#O/w
System.err.println(sMsg); h bdEw=r?
} f5N<3m=
} 'H FwP\HX
;7)OSGR
yh4jRe?f
/* i"KL;t[1
**TestMethod.java (kdC1,E
*/ JJ)y2
package NetFox; fg< (bXC
?F!W#
rg"TJ"Q-
public class TestMethod { e|35|I '
4h(jw
o<~-k,{5P
public TestMethod() ?@yank|
{ ///xx/weblogic60b2_win.exe 8x`Kl(
try{ `f2W;@V0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ipgN<|`?@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); [`cdlx?Eh
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,,zd.9n
fileFetch.start(); ZKZl>dDuh
} i=x.tsJ:hB
catch(Exception e){e.printStackTrace ();} Q>##hG:m
{c&qB`y<.
@G7w(>_T3
} ^n6)YX
G*8+h
rDK;6H:u{
public static void main(String[] args) ab8oMi`z
{ o",f(v&u%
new TestMethod(); <W=~UUsn
} jdV .{8@
} Tz+HIUIxF
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