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)); -m'a%aog
} L6 _Sc-sU
for(int i=0;i<nEndPos.length-1;i++) w4L\@y3
{ ^;@Bz~Z
nEndPos = nStartPos[i+1]; n+uq|sYVa
} )1x333.[c
nEndPos[nEndPos.length-1] = nFileLength; (OG@]|-
} /-|xxy
} mz\m^g3
>MQW{^
-IX;r1UD
//启动子线程 5,Q('t#J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8#Z$}?W
for(int i=0;i<nStartPos.length;i++) !uO|T'u0a
{ e:7aVOm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9oq(5BG,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cQ+,F2
nStartPos,nEndPos,i); :He:Bdk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p$9N}}/c
fileSplitterFetch.start(); ~o # NOfYi
} .{x5(bi0S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;( 2uQ#Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); q"52-42
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;=^WIC+Nr
nEndPos = " + nFileLength); tQl=
// fileSplitterFetch[nPos.length-1].start(); q0c)pxD%`
i;dr(c/ft
,MvvW{EY
//等待子线程结束 MPL2#YU/a
//int count = 0; / TJTu_#
//是否结束while循环 \'p7,F{:>5
boolean breakWhile = false; W}=2?vHV=
]iNSa{G
v#/,,)m
while(!bStop) lJYv2EZ
{ \uPT-M*
write_nPos(); 6|jE3rHw
Utility.sleep(500); 3t_5Xacj
breakWhile = true; &Y#9~$V=
HE,wEKp
A|a\pL`@
for(int i=0;i<nStartPos.length;i++) 3=K-+dhk|t
{ Ys3C'Gc
if(!fileSplitterFetch.bDownOver) G:&Q)_
{ l{pF^?K
breakWhile = false; Z$hxo)|
break; U)l>#gf8
} /KV@Ce\
} _|Dt6
if(breakWhile) !EW]:u
break; ~ZDdzp>
Q@j:b]Y9
q{5Vq_s\
//count++; OB^
//if(count>4) {U<htl4
// siteStop(); 4Sl^cKb$7
} eo,]b1C2n
6/n;u{|
mcR!P~"i
System.err.println("文件下载结束！"); 4{Ak|
} pucHB<R@bL
catch(Exception e){e.printStackTrace ();} V\xQM;
} ?nn,RBS-
Pb`sn5;
#,9|Hr%
//获得文件长度 bQ4 }no0
public long getFileSize() =1JRu[&]8
{ o._^
int nFileLength = -1; |JDJ{;o
try{ nbRg<@
URL url = new URL(siteInfoBean.getSSiteURL()); UM]wDFn'E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DxD0iJ=W
httpConnection.setRequestProperty("User-Agent","NetFox"); FG(`&S+,
@]7\.>)
ynd}w G'
int responseCode=httpConnection.getResponseCode(); oy'+n-
if(responseCode>=400) @Uu\x~3y
{ E:tUbWVp
processErrorCode(responseCode); rTJWftH!
return -2; //-2 represent access is error 8]L.E
} R.QcXz?d
?t"PawBWE
3HiW1*5W
String sHeader; x?F{=\z/o
p?h;Sv/
;|%r!!#-t
for(int i=1;;i++) I"!{HnSG`
{ :({<"H)!'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4CCux4)N
//Utility.log(in.readLine()); JQCwI`%i
sHeader=httpConnection.getHeaderFieldKey(i); !K2[S J
if(sHeader!=null) RAxz+1JT
{ &sWyh[`P
if(sHeader.equals("Content-Length")) kr/h^e
{ loB/w{r*x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j AE0$u~.
break; ,jWd?-NH
} X>4`{x`
} -jy"?]ve.
else Rju8%FRO
break; {3Rax5Ty
} ^/uGcz|.
} Rb0{t[IU
catch(IOException e){e.printStackTrace ();} tvUvd(8w
catch(Exception e){e.printStackTrace ();} }X?*o`sW
WWLVy(
_7<U[63
Utility.log(nFileLength); d7P @_jO6
ba ?k:b
KWUz]>Z
return nFileLength; 0_EF7`T
} *X #e
^m=%Ctu#
>KPJ74R
//保存下载信息（文件指针位置） ,W-0qN&%/
private void write_nPos() X3nhqQTZ
{ g2]-Q.
try{ O /&%`&2
output = new DataOutputStream(new FileOutputStream(tmpFile)); $5IrM7i
output.writeInt(nStartPos.length); QhUraZ
for(int i=0;i<nStartPos.length;i++) 75HL
{ .g~@e_;):
// output.writeLong(nPos); a\w|tf
output.writeLong(fileSplitterFetch.nStartPos); o~K2K5I
output.writeLong(fileSplitterFetch.nEndPos); -(.7/G'Vk>
} $yAfs3/%)s
output.close(); QFPx4F7(e
} c v 9 6F
catch(IOException e){e.printStackTrace ();} >N J$ac
catch(Exception e){e.printStackTrace ();} WdAGZUp
} Mvv=)?:
u^9c`
"Zk6B"o)
//读取保存的下载信息（文件指针位置） av?BpN"l
private void read_nPos() yh:,[<q
{ cZ>W8{G
try{ L'Zud,JKg
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3c3Z"JV
int nCount = input.readInt(); ^j %UZ
nStartPos = new long[nCount]; nS4S[|w"
nEndPos = new long[nCount]; pG6-.F;
for(int i=0;i<nStartPos.length;i++) gpWS_Dw9
{ [R>
nStartPos = input.readLong(); ][nUPl
nEndPos = input.readLong(); P{eRDQ=
} @W8}N|jek
input.close(); oNZW#<K
} l`&6W?C
catch(IOException e){e.printStackTrace ();} c5e\ckqm^
catch(Exception e){e.printStackTrace ();} [r8 d+
} MF}Lv1/[-J
>EtP^Lu~f_
HW726K*
private void processErrorCode(int nErrorCode) dA/o4co
{ 2H[aY%1T
System.err.println("Error Code : " + nErrorCode); Nh9!lBm*]
} ]ECZU
e0HP~&BRs
!d.>r 7w
//停止文件下载 !^fR8Tp9
public void siteStop() dY<#a,eS
{ ; ZV^e
bStop = true; ;|QR-m2/
for(int i=0;i<nStartPos.length;i++) acY[?L_6J
fileSplitterFetch.splitterStop(); v:MS0]
2TEeP7
RCYbRR4y
} "n }fEVJ,
} Q+(:n)G_6E
//负责部分文件的抓取 /'6[*]IZP
**FileSplitterFetch.java 9Fx z!-9m
*/ Ko)T>8:
package NetFox; T zYgH
43=-pyp
?]D+H%3[$i
import java.io.*; y%bqeo L~
import java.net.*; Os 2YZ<t
D{c>i`\G
BJxmW's/
public class FileSplitterFetch extends Thread { %@93^q[\2
NoZ4['NI\
_np>({
String sURL; //File URL Uv`v|S:+2
long nStartPos; //File Snippet Start Position jjT2k
long nEndPos; //File Snippet End Position 9~'Ip7X,!
int nThreadID; //Thread's ID MVP)rugU
boolean bDownOver = false; //Downing is over "Vp:z V<S
boolean bStop = false; //Stop identical -!G#")<
FileAccessI fileAccessI = null; //File Access interface 9c}]:3#XO
`AHNk7 t=
5zw23!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )|R0_9CLV
{ JS?l?~
this.sURL = sURL; [pgkY!R?)
this.nStartPos = nStart; ":#x\;
this.nEndPos = nEnd; w^E]N
nThreadID = id; x ETVtq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R 4QwWSBJ
} zw0 r i6
W#7-%oT
=tRe3o0(
public void run() -sH.yAvC6
{ 8tRhV2
while(nStartPos < nEndPos && !bStop) +Y9D!=_lj
{ eKpxskbhZ
_<F@(M5
?Wz(f{Hm
try{ "jJdUFN
URL url = new URL(sURL); 9hLmrYNM1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r]EZ)qp^@
httpConnection.setRequestProperty("User-Agent","NetFox"); X:-bAu}D
String sProperty = "bytes="+nStartPos+"-"; PSqtZN
httpConnection.setRequestProperty("RANGE",sProperty); $_7d! S"
Utility.log(sProperty); r]//Q6|S
nBIv{
'`~(Fkj
InputStream input = httpConnection.getInputStream(); `{Di*
//logResponseHead(httpConnection); p9}c6{Wp
$17 v,
4U a~*58
byte[] b = new byte[1024]; ="w8U'
int nRead; (VI* c!N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h:Mn$VR,
{ p C2c(4
nStartPos += fileAccessI.write(b,0,nRead); lyH X#]
//if(nThreadID == 1) V?V)&y] 4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Nw$[a$^n
} ^AjYe<RU}
'"fU2M<.
nP{sCH 1
Utility.log("Thread " + nThreadID + " is over!"); Z=Y_;dS9
bDownOver = true; q,,>:]f#
//nPos = fileAccessI.write (b,0,nRead); \%?8jQ'tX
} t"bPKFRy9E
catch(Exception e){e.printStackTrace ();} b}*@=X=4o
} I1 R\Ts@
} @1SKgbt>
031.u<_
5nM9!A\D
//打印回应的头信息 >-|90CSdSJ
public void logResponseHead(HttpURLConnection con) < J<;?%]
{ ic{.#R.BY
for(int i=1;;i++) +yP[(b/
{ 8&A|)ur4
String header=con.getHeaderFieldKey(i); 3|'#n[3
if(header!=null) JXRf4QmG
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (zw=qbS&
Utility.log(header+" : "+con.getHeaderField(header)); wI]R+.
else k E#_Pc
break; L[D/#0qp
} Rr;LV<q+
} vD)A)
T.w}6?2
$L&9x3+?Kg
public void splitterStop() B[/['sD
{ LY88;*:S
bStop = true; e<O;pM:
} Fb{`a[&
>upXt?
Aiks>Cyi23
} ~ut& U
ug6f
tp0!,ne*
/* e"s{_V
**FileAccess.java w{zJE]7
*//文件访问(定位，写) C`th^dqBV
package NetFox; B:A1W{l
import java.io.*; k.=S+#"}
(|a$N.e&K
R!V5-0%
public class FileAccessI implements Serializable{ Uygw*+
w(e+o.:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2) /k`Na
RandomAccessFile oSavedFile; .iP G/e
long nPos; leb^,1/D6
zmL~]!~&
fBWJ%W
public FileAccessI() throws IOException 5Du>-.r
{ K7[AiU_I
this("",0); X@h^T>["
} LcpyW=)}"V
=S[FJaIu7
6Er0o{iI
public FileAccessI(String sName,long nPos) throws IOException e2-70UvW^
{ (9YYv+GGd*
oSavedFile = new RandomAccessFile(sName,"rw"); |<$<L`xoe
this.nPos = nPos; O2'bNR
oSavedFile.seek(nPos); B )1<`nJA
} msqxPC^I
_L:i=.hxN
5fj
public synchronized int write(byte[] b,int nStart,int nLen) bDh:!M
{ ]lB3qEn<
int n = -1; .XLV:6
try{ T)Zt'M
oSavedFile.write(b,nStart,nLen); yjOu]K:X
n = nLen; An8%7xa7
} =ve*g&
catch(IOException e) .^W\OJ`G
{ (Xr_ np @
e.printStackTrace (); ENYF0wW
} 9#EHXgz
Q0L@.`~
m>abK@5na
return n; 7{Ki;1B[w
} P"V{y|2
,.6J6{
}W__ffH
} J2oWssw"
dY4k9p8
iBtjd`V*
/* [`hE^chd
**SiteInfoBean.java {#w A!>.
*/ 6m-:F.k1(
package NetFox; rt3f7 s*
f- k|w%R@
{ /F rs*AF
public class SiteInfoBean { Mf;|z0UX
U=&^H!LVY
]8xc?*i8
private String sSiteURL; //Site's URL c4ZuW_&:
private String sFilePath; //Saved File's Path T<TcV9vM
private String sFileName; //Saved File's Name _X,[]+ziu%
private int nSplitter; //Count of Splited Downloading File /slm ]'
*gM,x4Y
EI=Naq
public SiteInfoBean() V>FT~k_"
{//nSplitter的缺省值为5 d4y9AE@k
//default value of nSplitter is 5 JGk3b=K
this("","","",5); f.aB?\"f6
} Uw2,o|=O
|b$>68:
$S6HZG:N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }XGMa?WR
{ Z{,GZT
sSiteURL= sURL; 3wN?|N
sFilePath = sPath; Yo~LckFF
sFileName = sName; "wnpiB}
this.nSplitter = nSpiltter; ;t;Y.*&=S
?fbgU
@pF fpHq?>
} 5|<yfk8*J
M#\ <
E[|s>Xv~
public String getSSiteURL() %]a @A8o0
{ k#axt Sc
return sSiteURL; Snc;p
} 99l>CYXd
/~3N@J
y*VQ]aJ
public void setSSiteURL(String value) KA5~">l
{ ]^J+-c
sSiteURL = value; v`#j
} ,:#,}w_HyO
qj~flw1:
c;:">NR
public String getSFilePath() \)OZUch
{ u*t,i`
return sFilePath; NJ;"jQ-
} g$*/XSr(
fm(mO%
@4IW=V
public void setSFilePath(String value) up\oWR:
{ 0dgP
sFilePath = value; b]!9eV$
} G(U9rJ9
doP$N3Zm
v! 7s M
public String getSFileName() _GVE^yW~z
{ U@Z>/ q
return sFileName; nNt*} k
} yfmp$GO:
o&(wg(Rv
8YuJ8KC
public void setSFileName(String value) D(y+1^>
{ f~w>v
sFileName = value; wP[xmO-%
} NH7`5mF$
A/q2g7My
yJ!OsD
public int getNSplitter() Z[",$Lt
{ KcC!N{
return nSplitter; T vrk^!
} (GCG/8s
Iz DG&c
?Bo?JMV
public void setNSplitter(int nCount) OFc\fW#
{ x^A7'ad0
nSplitter = nCount; ""co6qo#>
} 1HMUHZT
} >\V6+$cNp
]UDd :2yt
zVSx$6eiU
/* f}^I=pS&
**Utility.java \+-zRR0
*/ +'%@!
package NetFox; 5L8&/EN9-
^:`oP"%-T
~12_D'8D[
public class Utility { "`pNH'
N_UQ
tAF]2VV(e
public Utility() \tY"BC4.
{ i+g~ Uj}h
pmD4j8F_
=I2@/,
} 4SgF,ac3r
?w-1:NWjt
//线程睡眠 S}[l*7
public static void sleep(int nSecond) 2 P=[
{ &VDl/qnaL
try{ 2d*_Qq1
Thread.sleep(nSecond); Fh K&@@_
} z v>Oh#
catch(Exception e) -"=)z/S
{ ~W<CE_/]k
e.printStackTrace (); +b^]Pz5
} NUCiY\td
} )l&D]3$6K
#%:c0=
//日志 2-~|Z=eGW
public static void log(String sMsg) F/>*Ifs
{ nZfs=@w:y
System.err.println(sMsg); U@'F%nHw
} owvS/"@
fAGctRGH
yub{8f;v
public static void log(int sMsg) v5_7r%Hiw
{ "+)K |9T#
System.err.println(sMsg); OOnX`
} g+xw$A ou
} 3X;{vO\a1
8'A72*dhX
>H>gH2qp
/* q/NY72tj0
**TestMethod.java #EDEYEW7
*/ ~:4~2d|
package NetFox; =.*98
`1Zhq+s
OR:[J5M)
public class TestMethod { qz!Ph5(
]dSK wxk
Bq@zaMv
public TestMethod() iib
{ ///xx/weblogic60b2_win.exe 5u r)uz]w8
try{ UZGDdP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }g|nz8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $IVwA
SiteFileFetch fileFetch = new SiteFileFetch(bean); "X04mQn15
fileFetch.start(); |t))u`~
} *RWm47
catch(Exception e){e.printStackTrace ();} /)EY2Y'
EF#QH _X
87V1#U^
} UL( lf}M
j?6X1cMq
2C$R4:Ssw)
public static void main(String[] args) Kc #|Z
{ ecj7BT[mLI
new TestMethod(); Dzl;-]S
} o%`Xa#*Ly
} im]g(#GnKh
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