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)); @!p bR(8
} Ibf~gr(j
for(int i=0;i<nEndPos.length-1;i++) 8y:/!rRN
{ ;x<5F+b
nEndPos = nStartPos[i+1]; mJxr"cwHl
} (vX) <Z !
nEndPos[nEndPos.length-1] = nFileLength; Zv]'9,cbk
} /esdtH$=
} 6=cfr; BH2
k8KRVXgx
yMG(FAyu
//启动子线程 z*V 8l*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; su$IXI#R-&
for(int i=0;i<nStartPos.length;i++) .7K)'
{ &9Y ^/W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <`$svM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @h&:xA56
nStartPos,nEndPos,i); rn$G.SMgz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Cn"_x
fileSplitterFetch.start(); 1Kjqs)p^
} ]I,(^Xq3a(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V0)bPcS/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^C=dq(i=[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Vc[aNpE
nEndPos = " + nFileLength); r'J="^k{
// fileSplitterFetch[nPos.length-1].start(); O]4v\~@-j
X<%`
K}t=Y
//等待子线程结束 Vu`5/QDq
//int count = 0; 1Clid\T,o
//是否结束while循环 uTShz3
boolean breakWhile = false; Z";&1cK
` 0$i^,}
/0Jf/-}ovn
while(!bStop) eA{nwtN
{ ^4b;rLfk@
write_nPos(); -9] ucmN
Utility.sleep(500); zq6)jHfq.
breakWhile = true; 9^L{)t>
lRk_<A
mEm=SpO[$o
for(int i=0;i<nStartPos.length;i++) t[e]AU[}
{ LR "=(
if(!fileSplitterFetch.bDownOver) ZZ>"LH
{ `@q\R-`
breakWhile = false; z!M #
break; <4LW.q
} F?z:[1(:
} vfd<qdi3p(
if(breakWhile) /0swrt.
break; ~6"=d
{q/;G!ON.S
A"B#t"
//count++; l4gF.-.GYF
//if(count>4) 4#Xz-5v
// siteStop(); !/a![Ne
} vbD""
"S]G+/I|iw
gSa!zQN6
System.err.println("文件下载结束！"); f, '*f:(
} w%?Zb[!&
catch(Exception e){e.printStackTrace ();} Z%Pv,h'Q
} zfD@/kU
&cWC&Ws"
GlHP`&;UH
//获得文件长度 mm9uhlV8
public long getFileSize() =F2`X#x_j
{ {2%'=v
int nFileLength = -1; 4Q!|fn0Sv
try{ p[O\}MAd#
URL url = new URL(siteInfoBean.getSSiteURL()); 86pA+c+U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g~ii^[W
httpConnection.setRequestProperty("User-Agent","NetFox"); d,b]#fj
1COSbi]
ih|;H:"^
int responseCode=httpConnection.getResponseCode(); SiYH@Wma
if(responseCode>=400) P L7(0b%
{ QuP)j1"X
processErrorCode(responseCode); i[?VF\Y(
return -2; //-2 represent access is error d8uDSy
} K'}I?H~P_
2,Aw6h;
m-6&-G#
String sHeader; ~ulcLvm:i
Q:j~ kutS|
i&1rf|
for(int i=1;;i++) C B`7KK
{ [8<0Q_?,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qgf\"s
//Utility.log(in.readLine()); Ge @qvP_
sHeader=httpConnection.getHeaderFieldKey(i); ^AShy`o^X
if(sHeader!=null) Z l;TS%$
{ 1:iB1TclP
if(sHeader.equals("Content-Length")) *8J0yv
{ id588Y78
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >=d 5Scix
break; !PA><F
} '`YZJ
} ]WzeJ"r {3
else ^9`|QF
break; joDqv,iW8
} `M*jrkM]x
} `T+w5ONn
catch(IOException e){e.printStackTrace ();} qw*) R#=
catch(Exception e){e.printStackTrace ();} P:_bF>r ?
0K6My4d{
r7sA;Y\
Utility.log(nFileLength); Q_Br{ `c
M KX+'p\w
LzJ`@0RrX
return nFileLength; sq;!5qK
} S[gACEZ =
3~Lsa"/
c5|sda{
//保存下载信息（文件指针位置） Vo6+|ztk|
private void write_nPos() vsyg u
{ n=PfV3B
try{ u(fZ^
output = new DataOutputStream(new FileOutputStream(tmpFile)); u|Oc+qA(
output.writeInt(nStartPos.length); Yg?BcY\
for(int i=0;i<nStartPos.length;i++) tUuARo7#
{ ${E^OE
// output.writeLong(nPos); A|,qjiEJCc
output.writeLong(fileSplitterFetch.nStartPos); +~BP~
output.writeLong(fileSplitterFetch.nEndPos); 7x=4P|(\}
} @)x*62r+
output.close(); ,a?oGi
} 3;FV^V'
catch(IOException e){e.printStackTrace ();} Fc80HK5R
catch(Exception e){e.printStackTrace ();} dF09_nw
} J2 /19'QE
]kXWeY<
a'`?kBK7`U
//读取保存的下载信息（文件指针位置） Ch3MwM5]
private void read_nPos() :h |]j[2p
{ q2r$j\L%
try{ o ^ \+Ua
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .P`QCH;Ih
int nCount = input.readInt(); $}r.fji,c
nStartPos = new long[nCount]; jV9oTH-
nEndPos = new long[nCount]; qp)Wt6 k?
for(int i=0;i<nStartPos.length;i++) BVj(Q}f8
{ liG|#ny{
nStartPos = input.readLong(); sa&`CEa
nEndPos = input.readLong(); O_ZYm{T[7
} :8j7}'
input.close(); &PH:J*?C}
} 4xq|
catch(IOException e){e.printStackTrace ();} HzKY2F(,
catch(Exception e){e.printStackTrace ();} :fwtPvLo
} UKZ)Boo
z6l'v~\
s3nO"~tM
private void processErrorCode(int nErrorCode) ;Vc|3
{ :b(W&iBWhI
System.err.println("Error Code : " + nErrorCode); {:("oK6w
} b=1E87i@W
\lm]G7h
^r.CUhx)
//停止文件下载 L'S,=NYXY
public void siteStop() OA=~i/n~
{ qljsoDG
bStop = true; 2_)UHTwsK
for(int i=0;i<nStartPos.length;i++) 9M3"'^ {$
fileSplitterFetch.splitterStop(); Osm))Ua(
Eyjsbj8
%7}j|eS)G
} 9]w?mHslE
} NU?<bIQ
//负责部分文件的抓取 K)wWqC.
**FileSplitterFetch.java TEY~E*=}$
*/ hmd3W`8D
package NetFox; CYQ)'v
G%: 3.:E"
(YYg-@IO
import java.io.*; GVJ||0D
import java.net.*; OR!W3 @
![_0GFbT
+)WU:aKI
public class FileSplitterFetch extends Thread { JffaT_"\
^d{5GK'
-,b+tC<V)0
String sURL; //File URL =#[oi3k
long nStartPos; //File Snippet Start Position ;m#4Q6k)V?
long nEndPos; //File Snippet End Position V`#2jDz
int nThreadID; //Thread's ID q)Nw$dW<
boolean bDownOver = false; //Downing is over b^C27s
boolean bStop = false; //Stop identical Ze8.+Ee
FileAccessI fileAccessI = null; //File Access interface x51R:x(p
viUJ4Pn
1w(3!Ps+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T:Nk9t$W7@
{ 1S!}su,uH
this.sURL = sURL; >@Ht*h{~
this.nStartPos = nStart; 4F G0'J&hw
this.nEndPos = nEnd; o.A:29KoU
nThreadID = id; ?YS>_MN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pKy4***I3
} &=jPt%7#M
6Q [
>FwK_Zd'
public void run() |r Aot2
{ QwWd"Of
while(nStartPos < nEndPos && !bStop) &`v?oN9$
{ {~&Q"8 }G
Vez8~r3
WIf.;B)L
try{ EG3,TuDH8
URL url = new URL(sURL); <6Gs0\JB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >h;]rMD!|
httpConnection.setRequestProperty("User-Agent","NetFox"); r4X}U|s!0
String sProperty = "bytes="+nStartPos+"-"; 4k@n5JNa
httpConnection.setRequestProperty("RANGE",sProperty); > B@c74
Utility.log(sProperty); >bze0`}Z
s. A}ydtt
EUuSN| a
InputStream input = httpConnection.getInputStream(); %eg+.
//logResponseHead(httpConnection); IJGw<cB]+
M=uT8JB
b;UDgq8v
byte[] b = new byte[1024]; pN5kcvQ
int nRead; 2.niB>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,GYQ,9:
{ }#H,oy;Dz
nStartPos += fileAccessI.write(b,0,nRead); >lUPOc
//if(nThreadID == 1) VnsV&cx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mXp#6'a
} X'PZCg W
}u O YF
vJ65F6=G
Utility.log("Thread " + nThreadID + " is over!"); I@ueeDY
bDownOver = true; )8W! |
//nPos = fileAccessI.write (b,0,nRead); }^Q:Q\
} Mt-r`W3 q
catch(Exception e){e.printStackTrace ();} 1l#46?]~
} j@z IJ
} HbA/~7
F5 ]<=i
M@.S Q@E
//打印回应的头信息 } jJKE
public void logResponseHead(HttpURLConnection con) lEFd^@t
{ H575W"53
for(int i=1;;i++) ?<!qF:r:
{ 1$vGQ
String header=con.getHeaderFieldKey(i); OA3J(4!"W
if(header!=null) MZ,1mR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b`#YJpA
Utility.log(header+" : "+con.getHeaderField(header)); ,7&\jET5^0
else (V6bX]<
break; I!Z`'1"
} ~hvj3zC5xz
} ~k?rP}>0
05FGfnq.8
S"h;u=5it
public void splitterStop() r$={_M$
{ JFm@jc
bStop = true; AuXUD9-
} z.cDbkf}
H1kI+YJ@
B&a{,.m&q6
} FFcCoPX_
Z2$_9.
`;6M|5G
/* ?CQE6ch
**FileAccess.java _f%s]
*//文件访问(定位，写) V@`b7GM
package NetFox; 5Z!$?J4Rl
import java.io.*; X#&5?oq`
!+PrgIp>
y5j:+2|I
public class FileAccessI implements Serializable{ Qjj }k)
M#'7hm6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Og7yT{h_
RandomAccessFile oSavedFile; gLv+L]BnhH
long nPos; jV sH
;\0|1Eem`
FLMiW]?x
public FileAccessI() throws IOException =Q_1Mr4O
{ gFTU9k<
this("",0); $#hU_vr
} oDA'$]UL
qIZ+%ZOu
.jQx2O
public FileAccessI(String sName,long nPos) throws IOException s1 >8uW
{ e`4mrBtz|
oSavedFile = new RandomAccessFile(sName,"rw"); =T[P
this.nPos = nPos; K]m#~J3d>
oSavedFile.seek(nPos); ?_gvI
} fxcE1=a
B9"o Ru^}
; pBLmm*F
public synchronized int write(byte[] b,int nStart,int nLen) #a}w&O";
{ h2zSOY{su
int n = -1; ~%*l>GkP*
try{ )jL@GW
oSavedFile.write(b,nStart,nLen); `C>h]H(
n = nLen; @sn:%/x_
} SdlO]y9E
catch(IOException e) Wmd@%K
{ 4xW~@meNB
e.printStackTrace (); mHMsK}=~
} q<E7qY+
/1LN\Eu
.$-;`&0cZ
return n; F[\T'{
} !6|_`l>G,
Jzf+"%lv
;b [>{Q;
} c_qox
X{#^O/
ph6/+[:
/* l^R:W#*+U
**SiteInfoBean.java -J63'bb7oi
*/ &pI\VIx ?
package NetFox; (Yj6|`
g=D]=&H
|h $Gs2
public class SiteInfoBean { yam'LF
)b nGZ8h99
i-0 :Fs
private String sSiteURL; //Site's URL &H# l*
private String sFilePath; //Saved File's Path jF6Q:`k
private String sFileName; //Saved File's Name 1R-0b{w[
private int nSplitter; //Count of Splited Downloading File 1<@lM8&.kO
JL_(%._J
<6]Hj2
public SiteInfoBean() .nIGs'P
{//nSplitter的缺省值为5 ,Z|O y|+'
//default value of nSplitter is 5 jR1^e$
this("","","",5); #p=+RTZ<
} 0 F8xS8vK+
j\KOKvY)
<8%+-[(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k7:ISjJ
{ t#M[w|5?
sSiteURL= sURL; 8Ie0L3d-
sFilePath = sPath; 7202N?a {
sFileName = sName; u@Gum|_=N
this.nSplitter = nSpiltter; ,^4"e (
t`&mszd~T
d+P<ce2G
} .))k
m?Jnb\0
7g8\q@',
public String getSSiteURL() jY9tq[~/
{ 56."&0
return sSiteURL; ([JFX@
} %\v
r_ 9"^Er
#@Tm5z
public void setSSiteURL(String value) 6UN{Vjr%`
{ WZA1nzRc
sSiteURL = value; y54RD/`-
} !N:w?zsp
#I ,c'Vj
%,N-M]Jf
public String getSFilePath() Qc9[/4R>
{ YS9)%F=X
return sFilePath; ]w)uo4<^J
} UWCm:eRQ
h9A=20fj
|%Y=]@f
public void setSFilePath(String value) kad$Fp39
{ %AgCE"!
sFilePath = value; BH^cR<<j
} A?ESjMy(R
W.7u6F`
{yBd{x<>/
public String getSFileName() 48GaZ@v
{ iQh:y:Jo1&
return sFileName; D1fUEHB}A8
} ]w8h#p
s;[64ca]Q
Wu?[1L:x
public void setSFileName(String value) ,l)AYu!q4F
{ e+MsFXnB8
sFileName = value; -fz(]d
} H#`&!p
\ ]h$8JwV
(n{!~'3
public int getNSplitter() 7sJGB^vM
{ p_sqw~)^%
return nSplitter; BI6`@}%7>
} 'Ya-;5Y]
,Hc,]TPC4
P6ugbq[x#e
public void setNSplitter(int nCount) 0[OlJMVf
{ TP/bPZY
nSplitter = nCount; +Kg3qS"
} %t-}dC&
} *5'l"YQ@1
w>#.id[k
y{qKb:~wv
/* 1b"3]?
**Utility.java BG@[m
*/ ^t)alNGos
package NetFox; v.]W{~PI2V
C'0=eel[
9O#?r82
public class Utility { ML_[Z_Q<z
w259':
2W`<P2IA
public Utility() :sb+jk
{ 2k""/xMF'
)pt#Pu
A v%'#1w<"
} h`p9H2}0
c:z<8#A}
//线程睡眠 [kg*BaG:
public static void sleep(int nSecond) p[gq^5WuC
{ '4d+!%2t
try{ q1o)l
Thread.sleep(nSecond); \wo'XF3:
} IDv|i.q3
catch(Exception e) r*s)T`T}}
{ |h1Y3
e.printStackTrace (); syLpnNx=
} E?P:!V=_
} !_UBw7Zm
<</ Le%
//日志 I!-5 #bxD
public static void log(String sMsg) 5oIgxy
{ HvVS<Ke
System.err.println(sMsg); @8GW?R
} 'uA$$~1
mq~L1<f
J#& C&S 2
public static void log(int sMsg) p^QB^HEV
{ IGtqY8
System.err.println(sMsg); (!`]S>_w9
} .9;wJ9Bw[
} 5%Q[X
rN^P//
7Cj6Kw5k
/* Tn8GLn
**TestMethod.java q!zsGf{
*/ JdeGQ
package NetFox; O:,Fif?;
LK[%}2me
X>y6-%@
public class TestMethod { b}#ay2AR
u0& dDZ
oVSq#I4
public TestMethod() :.M"M$MRp8
{ ///xx/weblogic60b2_win.exe @z)_m!yV1
try{ ${%*O}$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~'l.g^p bv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (Q09$
SiteFileFetch fileFetch = new SiteFileFetch(bean); FO5'<G-
fileFetch.start(); 55T c
} c,I|O' &k
catch(Exception e){e.printStackTrace ();} cU'^ Ja?%
Lcyj,R
$VCWc#
} $w$4RQk3n
7EAkY`Op
[8QE}TFic
public static void main(String[] args) lE?F Wt
{ Eo }mSd
new TestMethod(); xc+h Fx
} F$Q@UVA
} U0:tE>3`
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