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)); h!&sNzX
} &K^MNd
for(int i=0;i<nEndPos.length-1;i++) `P+(&taT
{ R4%P:qM
nEndPos = nStartPos[i+1]; 9+YD!y
} 5H,G-
nEndPos[nEndPos.length-1] = nFileLength; :<#`_K~'
} gM;}#>6
} XM Vq-8B0
[AEBF2OIv
o7&4G$FX~
//启动子线程 BdbJ< Is
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FqA3{
for(int i=0;i<nStartPos.length;i++) D y6$J3 r
{ N$?cX(|7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (g :p5Rl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), M/V(5IoP(
nStartPos,nEndPos,i); $mco0%$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zvv:dC/p<
fileSplitterFetch.start(); )He#K+[}^4
} fm1X1T.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %R0v5=2'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qUhRu>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", . ,NB( s`
nEndPos = " + nFileLength); KiLvI,9y
// fileSplitterFetch[nPos.length-1].start(); z)F#u:t
1H:ea7YVU
oL/o*^
//等待子线程结束 c-XLI
//int count = 0; FYPz 4K
//是否结束while循环 E(+T*
boolean breakWhile = false; 4YbC(f
e/e0d<(1
dhRJg"vrQ
while(!bStop) `0BdMKjA
{ a ib}`l
write_nPos(); ^[h2%c$
Utility.sleep(500); 2xmk,&s
breakWhile = true; (0*v*kYdL+
nYv#4*
^6/j_G
for(int i=0;i<nStartPos.length;i++) ;np_%?is
{ i8V0Ty4~N
if(!fileSplitterFetch.bDownOver) ]S8LY.Az5
{ CKARg8o
breakWhile = false; 6i@ub%qq
break; ` DCU>bt&R
} 0V11#
} >?XbU}
if(breakWhile) o0;7b>Tv
break; eFQQW`J
[J\DB)V/
+h[e0J|v{
//count++; p?rK`$U+J
//if(count>4) cV$lobqO
// siteStop(); L@|#Bbmx
} R$b,h
$"fo^?d/s
@vH2Vydu
System.err.println("文件下载结束！"); \v`#|lT$
} ^/KfH&E
catch(Exception e){e.printStackTrace ();} `\FI7s3b
} .A<sr
+802`eax
LZWS^77
//获得文件长度 |Mg }2!/L
public long getFileSize() 6zYaA
{ O.:I,D&]
int nFileLength = -1; D?u`
try{ SfI*bJo>V
URL url = new URL(siteInfoBean.getSSiteURL()); cqQRU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GfsBQY/
httpConnection.setRequestProperty("User-Agent","NetFox"); *m_93J
dXP6"V@iI
9={N4}<
int responseCode=httpConnection.getResponseCode(); >iy^$bqF
if(responseCode>=400) Fe="EDh
{ ?R?Grw)`H
processErrorCode(responseCode); r=csi
return -2; //-2 represent access is error A o3HX
} i>Iee^_(
gg8c7d:Q
GJak.,0t
String sHeader; .)ST[G]WK
1)U}i ^
F!CAitxd
for(int i=1;;i++) qc0 B<,x7
{ atnQC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ('WY5Yps
//Utility.log(in.readLine()); D9^7m j?e
sHeader=httpConnection.getHeaderFieldKey(i); oeNzHp_
if(sHeader!=null) #\b ;2>
{ a>b8-j=J
if(sHeader.equals("Content-Length")) [-VGArD[k,
{ Qq0O0U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E/"SU*Co
break; ``-k{C#F
} ;QidDi_s>
} IxP^i{/1?
else t-lv|%+8
break; uYTCdZQh
} #{>uC&jD
} eUs-5 L
catch(IOException e){e.printStackTrace ();} 4$i}Xk#3
catch(Exception e){e.printStackTrace ();} 56ZrCr
t&f" jPu>
cj^bh
Utility.log(nFileLength); FQ##397
Doj(.wm~
6h@+?{F.
return nFileLength; j)Lo'&Y~=
} JjDS"hK#
JX&~y.F
^N{X"
//保存下载信息（文件指针位置） >t,O2~
private void write_nPos() @H4wHlb
{ ^?sSx!:bZ
try{ 0x4l5x$8
output = new DataOutputStream(new FileOutputStream(tmpFile)); bZXlJa`'S
output.writeInt(nStartPos.length); =SL^>HS.fo
for(int i=0;i<nStartPos.length;i++) f\=6I3z
{ uH] m]t
// output.writeLong(nPos); 9/Wn!Ld
output.writeLong(fileSplitterFetch.nStartPos); w<mqe0
output.writeLong(fileSplitterFetch.nEndPos); ax]9QrA
} /'"R Mq
output.close(); .> ,Z kS
} (l2<+R%1
catch(IOException e){e.printStackTrace ();} rxArTpS{.#
catch(Exception e){e.printStackTrace ();} p`LL
} oo'iwq-\
'Dq"e$JM<
-rRz@Cr
//读取保存的下载信息（文件指针位置） _UaPwJ
private void read_nPos() Pd,!&
{ P8u"T!G
try{ 65t[vi*C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g.=!3e&z%
int nCount = input.readInt(); I'P.K| "R
nStartPos = new long[nCount]; qWkx:-g]
nEndPos = new long[nCount]; .;j"+Ef
for(int i=0;i<nStartPos.length;i++) >7W"giWP
{ #W.bZ]&WA
nStartPos = input.readLong(); 5%#i79z&B
nEndPos = input.readLong(); {6DpPw^"
} s?HsUD$b
input.close(); WE7>?H*Ro
} U<|B7t4M
catch(IOException e){e.printStackTrace ();} VgUvD1v?}
catch(Exception e){e.printStackTrace ();} @!Y.935/0
} cx<h_
Mru~<:9
MR[N6E6Mg
private void processErrorCode(int nErrorCode) [CsM<:C
{ ;\1b{-' l
System.err.println("Error Code : " + nErrorCode); +I?Qg
} >&g2 IvDS
*pY/5? g
j`Tm\!q
//停止文件下载 Y{`3`Pg&N
public void siteStop() s-fKh`
{ F1zT )wW
bStop = true; $]xE$dzJ
for(int i=0;i<nStartPos.length;i++) 1mAUEQ!
fileSplitterFetch.splitterStop(); 3{I=.mUUm
F%9e@{
e?|d9;BO
} 7O]J^H+7
} RT1{+:l
//负责部分文件的抓取 -wJ
**FileSplitterFetch.java j'#)~>b
*/ D<lQoO+
package NetFox; xq8}6Q
jt0H5-x
nYo&x'
import java.io.*; &E} I
import java.net.*; ' }y]mFpF
XL{{7%j
)*"T
public class FileSplitterFetch extends Thread { 6tDg3`w>
};4pZceV
`M towXj
String sURL; //File URL $K5ni{M;
long nStartPos; //File Snippet Start Position @'6S[zU
long nEndPos; //File Snippet End Position gK&5HTo
int nThreadID; //Thread's ID \HBVNBY
boolean bDownOver = false; //Downing is over N[- %0
boolean bStop = false; //Stop identical ){?mKB5
FileAccessI fileAccessI = null; //File Access interface ]Om'naD
Q"x`+?!
|?4~T:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .aVHd<M
{ !y[}|
this.sURL = sURL; S,ouj;B
this.nStartPos = nStart; dm/-}
this.nEndPos = nEnd; a>-}\GXTA
nThreadID = id; hg<"Yg=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (**-"o]HH
} cKvAR5|
w!=_
7UeE(=Hr5
public void run() bn^mL~
{ c+)36/; X
while(nStartPos < nEndPos && !bStop) "t3uW6&
{ AQJ|^'%
B;Q`vKY
j\i;'t}8g
try{ yBXkN&1=%;
URL url = new URL(sURL); A1#4nkkc9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !3b|*].B
httpConnection.setRequestProperty("User-Agent","NetFox"); W07-JHV%
String sProperty = "bytes="+nStartPos+"-"; yH0yO*RZ
httpConnection.setRequestProperty("RANGE",sProperty); i{1)=_$Vt`
Utility.log(sProperty); iMOPD}`IX
k8Su/U
8M".o n
InputStream input = httpConnection.getInputStream(); i4{ /
//logResponseHead(httpConnection); {Kq*5Aq8
pUCEYR
#2ZrdD"5kQ
byte[] b = new byte[1024]; EA%#/n
int nRead; Sh~ 8jEk
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9}'l=b:Jms
{ 5~ *'>y
nStartPos += fileAccessI.write(b,0,nRead); /jK17}j
//if(nThreadID == 1) flm,r<*}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }R(0[0NQe-
} ;ZE<6;#3IP
fmZzBZ_
b6?Xo/lJ.
Utility.log("Thread " + nThreadID + " is over!"); jiw`i
bDownOver = true; b& _i/n(
//nPos = fileAccessI.write (b,0,nRead); gs`27Gih
} a-UD_|!
catch(Exception e){e.printStackTrace ();} Bcd0
} |aOnV,}
} {8>_,z^P)
Js^r]=\F'
q)z1</B-
//打印回应的头信息 +"N<-
public void logResponseHead(HttpURLConnection con) C7fi1~
{ wZ\e3H z
for(int i=1;;i++) wzLiVe-
{ &s6(3k
String header=con.getHeaderFieldKey(i); Fm[?@Z&wP
if(header!=null) 46.q anh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e) /u>I
Utility.log(header+" : "+con.getHeaderField(header)); B#Oc8`1Y
else Lu#@~
break; /="D]K)%b8
} /S=;DxZ,r
} 6&xW9' 6b:
s_Ge22BZ
7]HIE]#
public void splitterStop() 'k(~XA}X:
{ C}DG'z9
bStop = true; TF}4X;3Dsy
} KSpC%_LC
w]+BBGYQKb
J!^~KN6[
} "ppb%=
nD?M;XN
<J_,9&\J
/* A](}"Pi!n
**FileAccess.java JXR/K=<^
*//文件访问(定位，写) !^"!fuoNC
package NetFox; /o06hy
import java.io.*; K&a]pL6D
'y@ 2,9v
f!R^;'a
public class FileAccessI implements Serializable{ %RD7=Z-z
'>WuukC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @v-)|8GdY
RandomAccessFile oSavedFile; 3b[[2x_UU
long nPos; u{lDof>
4;~lpty
Qc =lf$
public FileAccessI() throws IOException /dvnQW4}8
{ `R=_t]ie
this("",0); GHsdLe=t0#
} ujHzG}2z
>p#d;wK4_
eRqexqO!
public FileAccessI(String sName,long nPos) throws IOException DBh/V#* D
{ kE(-vE9
oSavedFile = new RandomAccessFile(sName,"rw"); j]F3[gpc
this.nPos = nPos; mM^8YL
oSavedFile.seek(nPos); U!UX"r
} A5H8+gATK
wTuRo J
lG^nT
public synchronized int write(byte[] b,int nStart,int nLen) ^A$XXH'
{ Sw9mrhzJfe
int n = -1; 7z0uj
try{ o6yZ@R
oSavedFile.write(b,nStart,nLen); FZ.Yn
n = nLen; D@1^:'$V
} `0vy+T5
catch(IOException e) yT9RNo/w
{ v@1Jhns
e.printStackTrace (); T`0gtSS
} qf&{O:,Z
q@yabuN@,j
<u%e*
return n; M#<fh:>
} lSv;wwEg
cx%9UK*c
*1]k&#s
} %iFIY=W
>N"PLSY1
!x /Z"
/* HSFf&|qqx
**SiteInfoBean.java -.3k vL
*/ <g1hdF0
package NetFox; *wyLX9{:
fszeJS}Dw
qCT\rZU
public class SiteInfoBean { /3%xQK>%
jmVy4* P_
jJC((1|
private String sSiteURL; //Site's URL TTak[e&j3
private String sFilePath; //Saved File's Path nezbmpL4
private String sFileName; //Saved File's Name 9 9BK/>R
private int nSplitter; //Count of Splited Downloading File ]KT,s].
7}85o J
3`8xh9O
public SiteInfoBean() HBGA lZ
{//nSplitter的缺省值为5 LZ dNG\-
//default value of nSplitter is 5 hvZR4|k>
this("","","",5); @x ]^blq
} Qn&^.e9I
}f*S 9V
bd;f@)X
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Bq`kVfx
{ sUMn (@r
sSiteURL= sURL; ay[*b_f
sFilePath = sPath; Lwk-
sFileName = sName; @b({QM|
this.nSplitter = nSpiltter; S*:w\nXP~
POs~xaZ`H
p8J"%Jq}
} ,KaWP
*&MkkI#
6GvnyJ{[
public String getSSiteURL() wB"Gw` D
{ ZK*aVYnu
return sSiteURL; JFdzA
} x*V<afLY[
[GM<Wt0
O,#[m:Ejb
public void setSSiteURL(String value) rNp#5[e
{ ??Ac=K\
sSiteURL = value; yK3z3"1M?
} F tjm@:X
i(rY'o2 BN
^123.Ru|t
public String getSFilePath() *h6i9V%'
{ PD4E&k
return sFilePath; LcF3P 4
} }FVX5/.'
g.s oNqt=
&.B6P|N'
public void setSFilePath(String value) F{tSfKy2
{ p7er04/}\
sFilePath = value; BZ9iy~
} "dTXT
~yN,FpD
{c;3$
public String getSFileName() dW68lVWq_
{ ]+P&Y:
return sFileName; Zlo,#q
} =oJiNM5_u
xkovoTzV
R3A^VE;qP
public void setSFileName(String value) 7/L7L5h<
{ -&}E:zoe
sFileName = value; %\0 Y1!Hw
} v'tk:Hm1
ri ~2t3gg
M-Bw9`#Jw
public int getNSplitter() CgC wM=!r
{ mZyTo/\0
return nSplitter; E12k1gC`
} D2bUSRrb
HJmO+
R8l9i2
public void setNSplitter(int nCount) xJCpWU3wM
{ xTT>3Fj
nSplitter = nCount; xFZq6si?
} s?Kn,6Y
} }T,uw8?f!
CggEAi~
O;2 u1p'iP
/* b3+PC$z2h
**Utility.java S6]':
*/ 1oPT8)[U
package NetFox; >q`X%&l_
"dOzQz*E
eAMT72_
public class Utility { zKNk(/y
`Nj|}^A
)T?ryp3ev
public Utility() KXJHb{?
{ k&b>-QP6
~ 4aaJ0
Lg1Usy%
} ,tZwXP{
)c/] 8KU
//线程睡眠 @_{"ho
public static void sleep(int nSecond) $4&Ql
{ `c(@WK4
try{ rzu^br9X
Thread.sleep(nSecond); ;QYK {3R?
} q)*0G*
catch(Exception e) ArY'NE\Htt
{ Z>l>@wNm
e.printStackTrace (); L6^h3*JyD
} s6B@:9
} Ty=}A MMyE
kbY@Y,:w
//日志 [C$ 0HW
public static void log(String sMsg) #_d%hr~d
{ }1V&(#H2
System.err.println(sMsg); |($pXVLH`
} +-hmITJv
?D_zAh?pW
DjIs"5Iei
public static void log(int sMsg) x>^S..K}L%
{ Gsb]e
System.err.println(sMsg); {8' 5
} ' vwBG=9C
} 6{M.S}.^
iaB5t<t1r
t`Sh!e
/* U&6f}=vC
**TestMethod.java :|a[6Uwl\V
*/ ydt1ED0Q-
package NetFox; QUt!fF@t
3r\QLIr L8
ZU`"^FQ3A
public class TestMethod { W>~V?%F&'
X\;y;pmRH
P.o W#Je
public TestMethod() .eE5pyw+C
{ ///xx/weblogic60b2_win.exe $)U RY~;i
try{ gnQd#`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); STI8[e7{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4T:ZEvdzf
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4Xz|HU?
fileFetch.start(); <*[(t;i
} 'Gk|&^
catch(Exception e){e.printStackTrace ();} D<MtLwH
\21!NPXH2
"k.<"pf
} jzQgDed ]
d^7<l_u~ !
!Ej<J&e
public static void main(String[] args) Rh=h{O
{ {?8rvAjY
new TestMethod(); ?^dyQhb
} 9:1ZL_yf
} S7bSR?~L[
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