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)); nIvJrAm4k
} 8L1ohj
for(int i=0;i<nEndPos.length-1;i++) 9Mgq1Z
{ d|iy#hy"_
nEndPos = nStartPos[i+1]; oQL59XOT4
} 8+Td-\IMk
nEndPos[nEndPos.length-1] = nFileLength; 2z@\R@F
} 1c@}C+F+
} >g;kJe
aIXdV2QS
)$Z=t-q
//启动子线程 $:of=WTY(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8#D:H/`'
for(int i=0;i<nStartPos.length;i++) A?*o0I
{ ^xZ e2@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v-! u\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c c
nStartPos,nEndPos,i); HQ9X7[3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W<<9y
fileSplitterFetch.start(); ~RD+.A
} aSP4a+\*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YKa0H%B(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); kHv[H]+v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "p3_y`h6+
nEndPos = " + nFileLength); 9TAj) {U%'
// fileSplitterFetch[nPos.length-1].start(); v{<[)cr
P5gN#G
[+Y{%U
//等待子线程结束 LA[g(i 7
//int count = 0; jp+_@S>
//是否结束while循环 Pe2wsR"_U
boolean breakWhile = false; dr<<!q /
(7DXRcr<
5ZY)nelc
while(!bStop) -<#!DjV6(
{ X1vNF|o~
write_nPos(); HBB{m
Utility.sleep(500); k'X;ruQ:tF
breakWhile = true; >Ng)k]G
5%}wV,Y
j:bgR8%e
for(int i=0;i<nStartPos.length;i++) a1j.fA
{ dC<LDxlv
if(!fileSplitterFetch.bDownOver) gf+d!c(/
{ y3<Y?M4
breakWhile = false; 1h7+@#<:a
break; ]/cd;u
} vOgC>_x7
} b|5w]<?'
if(breakWhile) auWXgkwZs/
break; rbZ[!LA
C;~*pMAYe
$Q+s/4\
//count++; wLV~F[:
//if(count>4) ~l~Tk6EM
// siteStop(); B[9 (FRX
} KL'zXkS
<:|3rfm#
tU/k-W3X
System.err.println("文件下载结束！"); q:8_]Qt
} voe7l+Xk
catch(Exception e){e.printStackTrace ();} F%rHU5CkV
} 8Q)@
x&A vUJ
+!0eu>~_&
//获得文件长度 n,O5".aa<
public long getFileSize() 6> {r6ixs1
{ M|io4+sy
int nFileLength = -1; l =IeJh
try{ y}08~L?2
URL url = new URL(siteInfoBean.getSSiteURL()); 0D~ C 5}/4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l|V;Ys5f
httpConnection.setRequestProperty("User-Agent","NetFox"); FP"$tt(
N]YtLa,t
Jg$xO@.
int responseCode=httpConnection.getResponseCode(); _;RVe"tR#
if(responseCode>=400) {I{:GcS
{ ,572n[-q
processErrorCode(responseCode); X%9*O[6{
return -2; //-2 represent access is error XUV!C7
} i.1U|Pi
uENdI2EY8y
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String sHeader; e1q"AOV6
R\s!*)
nF)uTk
for(int i=1;;i++) as"N=\N
{ [*m2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $(q>mg:H
//Utility.log(in.readLine()); y0ckm6^
sHeader=httpConnection.getHeaderFieldKey(i); P|jF6?C
if(sHeader!=null) SJgY
{ o{-<L
if(sHeader.equals("Content-Length")) E&~nps8e
{ giavJ|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7 boJ*
break; 3,aN8F1;C
} y~<@x.
} I]}>|
else {fSfq&o
break; 1q.(69M
} p D=w>"
} tu%[p 4
catch(IOException e){e.printStackTrace ();} gY9\o#)<
catch(Exception e){e.printStackTrace ();} +'03>!V
J7i+c];!<
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Utility.log(nFileLength); :wgfW .w
tjv\)Nn'
rlznwfr7+
return nFileLength; QYThW7S
} 2>hz_o{5',
2RppP?M!
(%<'A
//保存下载信息（文件指针位置） ]re'LC!d
private void write_nPos() $EBb"+Y'T
{ Jfg7\&|
try{ So4nJ><p
output = new DataOutputStream(new FileOutputStream(tmpFile)); s'_,:R\VM>
output.writeInt(nStartPos.length); b7h+?!H]R
for(int i=0;i<nStartPos.length;i++) P -Fg^tl
{ 'dt\db5p
// output.writeLong(nPos); 4Nmea-!*
output.writeLong(fileSplitterFetch.nStartPos); C9KWa*3
output.writeLong(fileSplitterFetch.nEndPos); S_8r\B[>P
} =3ADT$YHd
output.close(); AZZRa69=
} PJ 9%/Nrh
catch(IOException e){e.printStackTrace ();} E20 :uZ7\
catch(Exception e){e.printStackTrace ();} U w Eiz
} %%g-GyP 1
{K7YTLWY
V_a)jJ
//读取保存的下载信息（文件指针位置） ESDB[ O+`x
private void read_nPos() %<}=xJf>1
{ ; Zq/eiB
try{ ?y-s20Kd
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A0#Y, 1
int nCount = input.readInt(); Jyu`-=It
nStartPos = new long[nCount]; mtw9AoO
nEndPos = new long[nCount]; e.X@] PQJQ
for(int i=0;i<nStartPos.length;i++) n,KA&)/s
{ 3ps,uozj
nStartPos = input.readLong(); C{Blqf3V0
nEndPos = input.readLong(); 5}a"?5J^
} \f"?Tv-C'
input.close(); A8dI:E+$
} 8wF#e\Va0
catch(IOException e){e.printStackTrace ();} Gc;B[/:
catch(Exception e){e.printStackTrace ();} 9e5gy
} 4 iH&:Al
v.`+I-\.z)
.s};F/(diD
private void processErrorCode(int nErrorCode) dERc}oAh(
{ H~m]nV,r
System.err.println("Error Code : " + nErrorCode); #AncOo
} u7muaSy
`-D$Fsl
VG#Q;Xd}
//停止文件下载 sb'p-Mj
public void siteStop() _pSIJ3O
{ "=A|K~b
bStop = true; B| Q6!
for(int i=0;i<nStartPos.length;i++) 0$2={s4ze
fileSplitterFetch.splitterStop(); K/Jk[29"\
KO-a; [/
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} qeMv Vf
} @+dHF0aXd
//负责部分文件的抓取 oEAfowXSqk
**FileSplitterFetch.java uL>:tb
*/ eycV@|6u*
package NetFox; 'rx?hL3VW
6_ ]8\n
^/{4'\p
import java.io.*; e\~l!f'z
import java.net.*; {8ECNQ[]
cQ,9Rnfl,
;o >WXw
public class FileSplitterFetch extends Thread { Ej|A ; &E
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String sURL; //File URL c *1S}us
long nStartPos; //File Snippet Start Position 0UD"^zgY
long nEndPos; //File Snippet End Position 1"$R 3@s;
int nThreadID; //Thread's ID tDU}rI8?
boolean bDownOver = false; //Downing is over M c@GH
boolean bStop = false; //Stop identical )l{A{f6O
FileAccessI fileAccessI = null; //File Access interface bs:QG1*.
2[BA(B
uRGB/ju^E
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ps7_-cH
{ @Mr}6x*
this.sURL = sURL; s7|3zqi
this.nStartPos = nStart; R2Yl)2 D
this.nEndPos = nEnd; Jy`G]]?
nThreadID = id; \-G5l+!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 eE,;K1
} O*4gV}:G
?'f^X$aS
6JWGu/A
public void run() U6a zhi&,
{ SW=aHM
while(nStartPos < nEndPos && !bStop) 1t%<5O;R
{ wQw-:f-
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.$^wy3:F"
try{ ] ?9t-
URL url = new URL(sURL); c85O_J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r_=p,#}#
httpConnection.setRequestProperty("User-Agent","NetFox"); .m!s". ?[
String sProperty = "bytes="+nStartPos+"-"; sZEgsrJh
httpConnection.setRequestProperty("RANGE",sProperty); E- KK
Utility.log(sProperty); @>CG3`?}
b.,$# D{p
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InputStream input = httpConnection.getInputStream(); 1)gv%_
//logResponseHead(httpConnection); 776 nWw)
!*8#jy
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byte[] b = new byte[1024]; 3z$HKG
int nRead; L77EbP`P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #Wq#beBb
{ -sx-7LKi
nStartPos += fileAccessI.write(b,0,nRead); VlV)$z_
//if(nThreadID == 1) 8k%H[Smn:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yd.027
} ^^'[%ok
=E; #OZO
CHg]Ul
Utility.log("Thread " + nThreadID + " is over!"); Z3Gm
bDownOver = true; o6:45
//nPos = fileAccessI.write (b,0,nRead); +&?'KZ+Z_v
} l&$*}yCK
catch(Exception e){e.printStackTrace ();} H}(=?}+
} `TAcZl=8
} 6l<1A$BQ
I=K[SY,]9
L[1d&d!p
//打印回应的头信息 OAY8,C=M
public void logResponseHead(HttpURLConnection con) oAC^4-Ld
{ i@Vs4E[b
for(int i=1;;i++) v=j>^FZ
{ G u6[{u
String header=con.getHeaderFieldKey(i); >]^>gUmq
if(header!=null) Io09W^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 98jD"*W5
Utility.log(header+" : "+con.getHeaderField(header)); E+:.IuXW$
else G~O" /WM
break; 2[XltjO
} 0&f\7z
} ~DK F%}E
}]tFz}E\
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public void splitterStop() ::0aY;D2
{ G^ K*+
bStop = true; AmgWj/>
} >@z d\}@W
j,Pwket
m\1VF\
} ~NA1SZ{Y+
!+5C{Hs2
4Fh&V{`W
/* vP-3j
**FileAccess.java NYGmLbq
*//文件访问(定位，写) C+T&O
package NetFox; 'n>EEQyp'
import java.io.*; `D4oAx d9
Ck:#1-t8{
Al=(sHc'
public class FileAccessI implements Serializable{ T4Xtuu1
_r~!O$2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G OH
RandomAccessFile oSavedFile; ,0BR-#
long nPos; 4c
#_on{I
]sf2"~v
public FileAccessI() throws IOException zoJ_=- *s
{ Wk7L:uK
this("",0); };i&a%I|
} c6f|y_2
D!c1;IHZ
wwo(n$!\
public FileAccessI(String sName,long nPos) throws IOException j!6elzg
{ n9N#&Q"7m
oSavedFile = new RandomAccessFile(sName,"rw"); $+A%ODv
this.nPos = nPos; a|8|@,
oSavedFile.seek(nPos); ,LoMt ]H
} &b5T&-C<
vYYS.ve
dK[*
public synchronized int write(byte[] b,int nStart,int nLen) _{[k[]
{ s*aH`M7^0
int n = -1; +Gk! t]dy
try{ '2wXV;`
oSavedFile.write(b,nStart,nLen); ,Le&I9*%
n = nLen; Y;'VosTD
} F_ ,L2J
catch(IOException e) ;r gH}r
{ x-w`KFS
e.printStackTrace (); AD~~e% s=
} 5{8x*PSl
pQk=x T
[`y:M&@
return n; C}n[?R
} MMd0O X)P
TS\9<L9S
Uc_'3|e
} LDT'FwMjy
z0\;m{TH
Y1#-^,qg
/* oq=?i%'>
**SiteInfoBean.java 7(yXsVq
*/ <QYCo1_
package NetFox; FE0qw1{qQ
@SKO~?7T
Y1$#KC
public class SiteInfoBean { sN6 0o 7.
6V.awg,
MV Hz$hyB
private String sSiteURL; //Site's URL l81&[
private String sFilePath; //Saved File's Path 6(ka"Vu~
private String sFileName; //Saved File's Name L@)b%Q@a
private int nSplitter; //Count of Splited Downloading File R59e&
3~cS}N T
h5LJijJ
public SiteInfoBean() 4RK.Il*d
{//nSplitter的缺省值为5 Bpk@{E9
//default value of nSplitter is 5 >k$[hk*~
this("","","",5); @ChN_gd3!
} mXxZM;P[
dNR7e
r24\DvS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZcUh[5:|
{ V-?sek{;
sSiteURL= sURL; P@gu~!
sFilePath = sPath; 8+*g4=ws
sFileName = sName; DBu)xr}7A
this.nSplitter = nSpiltter; EpFIKV!
;J,,f1Vw
g_rA_~dh
} d[s;a.
1?/5A|?V4+
30sC4}
public String getSSiteURL() ?F?\uC2)'
{ j\XX:uU_
return sSiteURL; S(g<<Te
} "i!2=A8k
&LCUoTzj
2 ||KP|5@
public void setSSiteURL(String value) %f_)<NP9=
{ !~Hafn-1
sSiteURL = value; (hhdbf
} 5@w'_#!)
BxSk%$J
xm<5S;E5U4
public String getSFilePath() :0J-ek.;
{ gt2>nTJz.Z
return sFilePath; eEZ|nEU
} K B`1%=
(&9DB
#U",,*2
public void setSFilePath(String value) m~= ]^e
{ DuTlYXM2^
sFilePath = value; 2.HZ+1
} 'U|MM;(
9J-!o]f .b
NDs]}5#
public String getSFileName() 9 NGeh*`
{ Z4wrXss~
return sFileName; p%1xj2 ?nN
} 7$q2v=tH_
tF#b&za
s8f3i\1
public void setSFileName(String value) 6T{o3wc;
{ *sc0,'0
sFileName = value; wzNt c)~i
} Q70**qm
>/kPnpJ
H 'WFORso[
public int getNSplitter() h-?q6O/|
{ `&|l;zsS
return nSplitter; (/9.+V_
} aIn)']
+eV4g2w)
jza}-=&+e
public void setNSplitter(int nCount) }\`-G+i{W
{ *0Wi^f
nSplitter = nCount; H}jK3;8E
} 1A`?y& Ll
} 6]@|7|N>X
i-i}`oN
MrKU,-
/* |mQtjo
**Utility.java )"pxry4v7J
*/ <6}f2^
package NetFox; c]g<XVI
>'2w\Uk~:
OIXAjU*N
public class Utility { PtPGi^
Dj,+t+|
lt2Nwt0bv
public Utility() Zgy2Pot
{ .qb_/#Bas
/C,>
|ZST Y}RXA
} ?|Q5]rhs
VtzyB
//线程睡眠 .qqb>7|q
public static void sleep(int nSecond) \ ]kb&Qw
{ Ye\*b?6
try{ {g!exbVf
Thread.sleep(nSecond); _Pfx_+
} #v~S",*.f
catch(Exception e) Q#J>vwi=
{ >F\rBc&
e.printStackTrace (); XTi0,e]5{u
} $3]E8t
} (4{@oM#H6
oQ-|\?{;A
//日志 hD6ur=G8u
public static void log(String sMsg) 02# b:
{ FB=
System.err.println(sMsg); ^qId]s
} qV,$bw
qy42Y/8'
Zjp5\+hHV
public static void log(int sMsg) eJ=Y6;d$
{ u\1Wkxj
System.err.println(sMsg); iRj x];:Vu
} d4/`:?w
} KWigMh\r
zZ+LisSs&
BJO~$/R?v
/* _OknP2E
**TestMethod.java Xb+if
*/ q/w6sQx$
package NetFox; T`w};]z^d2
*09\\ G
qK6 uU9z
public class TestMethod { 21/a3Mlx#
GdfKxSO
'De'(I
public TestMethod() m[xf./@f{
{ ///xx/weblogic60b2_win.exe P=SxiXsr$
try{ 9a~BAH,j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *p#YK|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); XvzV lKL
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?/l}(t$H
fileFetch.start(); Xv5Ev@T
} Y(I*%=:$
catch(Exception e){e.printStackTrace ();} |H+k?C-w
3]kAb`9[K2
C1Pt3
} `.sIZku
^K77V$v
.J6j"
public static void main(String[] args) 9J;H.:WH
{ ^qzT5W\@
new TestMethod(); Alk* "p
} l~6SR
} e2hk
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