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)); h1fJ`WT6,
} {0QD-b o
for(int i=0;i<nEndPos.length-1;i++) aEXV^5;,pJ
{ \#tr4g~u
nEndPos = nStartPos[i+1]; qfC9 {gu
} a&L8W4
nEndPos[nEndPos.length-1] = nFileLength; Y+upZ@Ga
} )%X\5]w`
} wVE"nN#
SZG8@ !_}7
"$0f.FO:i
//启动子线程 W$gSpZ_7
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; a6WE,4T9
for(int i=0;i<nStartPos.length;i++) 6e |
{ Aplqxvth
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =eac,]31
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Uw61X>y=
nStartPos,nEndPos,i); sf\;|`}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P_-zkw
fileSplitterFetch.start(); +hjc~|RK
} Zu%_kpW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2_r}4)z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >ID 3oi
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b%$S6.
nEndPos = " + nFileLength); 4 CX*,7LZ
// fileSplitterFetch[nPos.length-1].start(); A ,LAA$
C+5^[V
@GnsW;$*~.
//等待子线程结束 ]Wd{4(b
//int count = 0; 42z9N\ f
//是否结束while循环 ]qVJ>
boolean breakWhile = false; y H+CyL\
G#dpSNV3|
5R"b1
while(!bStop) CdZ;ZR
{ &~E=T3
write_nPos(); DT9i<kl
Utility.sleep(500); C 2oll-kN
breakWhile = true; ^D.B^BR
B|,6m 3.
KL5rF,DME
for(int i=0;i<nStartPos.length;i++) ~PlwPvWo
{ 5I&^n0h|&
if(!fileSplitterFetch.bDownOver) Iu1P}R>C
{ 9s*Lzi[}
breakWhile = false; E\V>3rse
break; ni%^w(J3Q
} ;"Ot\:0
} @ K@~4!
if(breakWhile) pY8+;w EI
break; ?erDP8
2lp.Td`{
HNh=igu
//count++; ;quGy3
//if(count>4) "9WP^[
// siteStop(); IZ2#jSDn
} U_VD* F4Bv
;U7\pc;S
YRYrR|I
System.err.println("文件下载结束！"); Ok:@F/ v
} DJn>. Gd
catch(Exception e){e.printStackTrace ();} V9<[v?.\
} 7#g C(&\A
F`u{'w:Hv
yv'rJI~ Ps
//获得文件长度 Oi7=z?+j
public long getFileSize() ;<&s_C3
{ Tu6he8Q-
int nFileLength = -1; p!Gf^
try{ ?` `+OH
URL url = new URL(siteInfoBean.getSSiteURL()); OOk53~2id
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1:>RQPXcWv
httpConnection.setRequestProperty("User-Agent","NetFox"); Q'|cOQX
<0kRky$
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int responseCode=httpConnection.getResponseCode(); {M%"z,GL7J
if(responseCode>=400) )>[(HxvfJU
{ d>AVUf<o~
processErrorCode(responseCode); T8KhmO
return -2; //-2 represent access is error a"&Z!A:Z=
} sztnRX_
huq6rA/i
71)#'ey
String sHeader; t]@Zd*
P' J_:\
@+{S-iD"
for(int i=1;;i++) !^m5by
{ _nRshTt`V&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K^w9@&g6
//Utility.log(in.readLine()); H@ w6.[#
sHeader=httpConnection.getHeaderFieldKey(i); J]~fv9~P
if(sHeader!=null) C$(t`G
{ }pTj8Tr
if(sHeader.equals("Content-Length")) -B4v1{An
{ =Q|}7g8o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 9 /zz@
break; NFa ;
} 2 G"p:iPp
} ? {&#l2
else m+u>%Ys`
break; .(Pe1pe
} sO
} 4p-$5Fk8}
catch(IOException e){e.printStackTrace ();} -p;oe}|
catch(Exception e){e.printStackTrace ();} 4]+ ^K`
6F(yH4
Zq`bd55~
Utility.log(nFileLength); ,v6Jr3
Ke/P[fo
H?~u%b@
return nFileLength; IB?A]oN1{
} Xt7'clr
21WqLgT3 4
z`Q5J9_<cV
//保存下载信息（文件指针位置） NV91{o(-7
private void write_nPos() b1&{%.3[
{ uo65i 1oi
try{ BsRas
output = new DataOutputStream(new FileOutputStream(tmpFile)); pIrAGA;
output.writeInt(nStartPos.length); D!<$uAT
for(int i=0;i<nStartPos.length;i++) 0 /kbxpih
{ H\b5]q%
// output.writeLong(nPos); zHU#Jjc_b
output.writeLong(fileSplitterFetch.nStartPos); .*f;v4!
output.writeLong(fileSplitterFetch.nEndPos); >3kR~:;
} J`8>QMK^5
output.close(); s<dD>SU
} @t2 Q5c
catch(IOException e){e.printStackTrace ();} P0Jd6"sS"
catch(Exception e){e.printStackTrace ();} $x)'_o}e
} $e;!nI;z
dyp]y$
q+:(@w6
//读取保存的下载信息（文件指针位置） feopO j6~+
private void read_nPos() Ab"uN
{ 8qc%{8
try{ (o:CxhV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jK=*~I
int nCount = input.readInt(); (G"qIw
nStartPos = new long[nCount]; *c%@f<R~
nEndPos = new long[nCount]; ^&<*$Ai~
for(int i=0;i<nStartPos.length;i++) s7 KKH w
{ c%U$qao=c+
nStartPos = input.readLong(); 6vjB;uS[
nEndPos = input.readLong(); @uE=)mP@
} B~aOs>1 S]
input.close(); I[`2MKh
} !Q3Snu=
catch(IOException e){e.printStackTrace ();} %zD-gw>
catch(Exception e){e.printStackTrace ();} UxvsSHi
} ~pA;j7*
FKx9$B
p%ZiTrA1&D
private void processErrorCode(int nErrorCode) pd;-z
{ 6nfkZvn
System.err.println("Error Code : " + nErrorCode); '?>eW2d
} Q)@1:(V/
O1ha'@qID
Y1'.m5E
//停止文件下载 I>3]4mI*a
public void siteStop() 8k1r|s@d
{ ygW@[^g
bStop = true; 'f}S,i +q
for(int i=0;i<nStartPos.length;i++) C~;0A!@]Y
fileSplitterFetch.splitterStop(); bsP;
]~.J@ 1?
7gMtnwT
} KVcZ@0[S
} CU;nrd"
//负责部分文件的抓取 yUSB{DLpla
**FileSplitterFetch.java -5cH$]1\
*/ bGi_", 8
package NetFox; !bcbzg2d&
)ra66E
F=om^6G%X5
import java.io.*; 5Hm!5:ZB
import java.net.*; 9aU:[]w
GA_`C"mx
Riw7<j
public class FileSplitterFetch extends Thread { Q kZM(pG
eE{L>u
:.Qe=}9
String sURL; //File URL uBTT {GGQ
long nStartPos; //File Snippet Start Position U>+~.|'V9
long nEndPos; //File Snippet End Position N39nJqo>"
int nThreadID; //Thread's ID QP[a^5;Tt
boolean bDownOver = false; //Downing is over u,akEvH~a
boolean bStop = false; //Stop identical U&n>fXTHn
FileAccessI fileAccessI = null; //File Access interface $048y X 7M
KYu(H[a
]Z-oUO Z<k
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $ tNhwF
{ !:<UgbiVv
this.sURL = sURL; M&ij[%i
this.nStartPos = nStart; ]jb4Z
this.nEndPos = nEnd; k2uiu
nThreadID = id; U+"=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `zp2;]W
} cQ.;dtT0
hu|hOr8
icul15'i
public void run() @,4%8E5
{ Kyp0SZp[
while(nStartPos < nEndPos && !bStop) i+[3o@
{ '= <`@
<gdgcvd
b H?qijrC
try{ 8>{W:?I
URL url = new URL(sURL); Hm VTfH'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); daIL> c"
httpConnection.setRequestProperty("User-Agent","NetFox"); ?GNF=#=M
String sProperty = "bytes="+nStartPos+"-"; "x;k'{S
httpConnection.setRequestProperty("RANGE",sProperty); ,GJ>vT)
Utility.log(sProperty); T4=3VrS
E)O|16f|>
K)`:v|d
InputStream input = httpConnection.getInputStream(); 1 j12Qn@]
//logResponseHead(httpConnection); bez'[Y{
R5eB,FN
-t6R!ZI
byte[] b = new byte[1024]; p,iCM?[|
int nRead; zf,%BI[Hr
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3rdfg
{ UY-IHz;&O-
nStartPos += fileAccessI.write(b,0,nRead); B`B%:#
//if(nThreadID == 1) %i-lx`U
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "q^#39i?
} S[~O')
]rg+nc3
Px#QZZ
Utility.log("Thread " + nThreadID + " is over!"); [Hj'nA^
bDownOver = true; qX+gG",8
//nPos = fileAccessI.write (b,0,nRead); cvUut^CdK
} A3$aMCwKd
catch(Exception e){e.printStackTrace ();} 8F^,8kIR
} RF5q5<0
} |R;l5ZKvV
^Y7/Ow
}utNZhJ
//打印回应的头信息 V`\f+Uu
public void logResponseHead(HttpURLConnection con) `cP'~OT
{ C5+`<
for(int i=1;;i++) So=nB} b[?
{ oKYhE
String header=con.getHeaderFieldKey(i); aw/7Z`
if(header!=null) @mx$sNDkL
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \$'m^tVU
Utility.log(header+" : "+con.getHeaderField(header)); 7y)=#ZG'R
else *1W,Mzg
break; tP`G]BCbt
} QM ZUt
} '}Wu3X
`(,*IK a
?7uKP}1|
public void splitterStop() v1nQs='
{ Fi'M"^:r{
bStop = true; z]c,}Q
} Q)Iv_N/
icPp8EwH
'cZMRRc<
} =zm0w~']E!
V3mjbH>F
*IWFeu7y
/* r]8x;v1
**FileAccess.java VyWYfPK
*//文件访问(定位，写) ov`^o25f
package NetFox; ?+n&hHRg
import java.io.*; qByNHo7Tb
i Y*o;z,~
ypD<2z^
public class FileAccessI implements Serializable{ z!s.9
+9zJlL^A%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VW9>xVd4
RandomAccessFile oSavedFile; UZje>.~?
long nPos; {}_Nep/;
oWp}O?
ZU|6jI}
public FileAccessI() throws IOException dP$8JI{
{ 2.LJp}>
this("",0); +Y>"/i. N
} ~=:2~$gsn
U{uPt*GUd/
uC,"5C
public FileAccessI(String sName,long nPos) throws IOException l'*^$qc
{ U*3AM_w
oSavedFile = new RandomAccessFile(sName,"rw"); ietRr!$.
this.nPos = nPos; )MWUS;O<
oSavedFile.seek(nPos); A%Bgp?B
} z\fW )/
-)1-~7 r
+yf(Rs)!
public synchronized int write(byte[] b,int nStart,int nLen) GilQtd3\
{ A~Z6jK
int n = -1; 1,"I=
try{ ~+O`9&
oSavedFile.write(b,nStart,nLen); 4\LZD{
n = nLen; rv9B}%e
} #NvQmz?J?
catch(IOException e) bTLMd$
{ FXP6zHsV
e.printStackTrace (); b?_e+:\UV
} Ih.rC>)rx
@$qOW
z`k El@
return n; No`|m0 :j
} .sM<6;
#D+7TWDwNt
t})lr\
} EL^8zyg%%
))7LE|1l
eV"!/A2:N5
/* 'X =p7 d|'
**SiteInfoBean.java )~ 0}Et l
*/ o:2Q2+d
package NetFox; D.'h?^kA
JD6aiI!Su
C5P$&s\
public class SiteInfoBean { w8O" =},
IY=/`g
AXwaVLEBQ
private String sSiteURL; //Site's URL 8b|OXWl
private String sFilePath; //Saved File's Path u!Xb?:3uj
private String sFileName; //Saved File's Name & _; y.!
private int nSplitter; //Count of Splited Downloading File 2w+U$6e C
lnS(&`oh\=
L7'%;?Z
public SiteInfoBean() UMV)wy|j
{//nSplitter的缺省值为5 @;vNX*-J
//default value of nSplitter is 5 z{9=1XY
this("","","",5); +l`65!"
} 'Qa5n\HX$
N0i!l|G6
w OI^Q~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -fE.<)m=!
{ (Uk>?XAr
sSiteURL= sURL; xc9YM0B&
sFilePath = sPath; @@I7$*
sFileName = sName; s~*}0-lS
this.nSplitter = nSpiltter; 9Ycn0
xJ{_qP
/F.Wigv
} ,LDm8
#05jC6
lVz9k
public String getSSiteURL() vw2`:]Q+
{ {_?rh,9q
return sSiteURL; S,)d(g3>
} k1)%.pt%
? B@&#E!/f
9mlIbEAb
public void setSSiteURL(String value) 'OwyyPBF
{ #B8*gFZB
sSiteURL = value; 1B|8ZmFJj
} Z$p0&~
,apNwkY
`K*b?:0lp
public String getSFilePath() B z^|SkEit
{ q2hFOm
return sFilePath; %SrM|&[
} j9d!yW
>I}9LyZt
xl(@C*.sC1
public void setSFilePath(String value) `s|]"'rX
{ L*h{'<Bz
sFilePath = value; 7FLXx?nLY
} )=J5\3O*x
?+~cA^-3T
O}Hf62"
public String getSFileName() fH\X
{ $=B8qZ+
return sFileName; |Os6V<u"
} !d,8kG
Qck|#tc
u7fK1 ^O
public void setSFileName(String value) S${Zzt"
{ 7Ym(n8
sFileName = value; oRM)%N#
} Yw'NX5#)g
).5RPAP
Df4+^B,1
public int getNSplitter() 5!I4l1
{ Q8D&tJg
return nSplitter; 8'Z:ydj^,
} ]0c+/ \b&
|F[=b'?
\(~wZd
public void setNSplitter(int nCount) !ErH~<f%K
{ 6KHN&P
nSplitter = nCount; R\mR$\cS
} x}TS
} p8}(kHUp(
QSw<%pcJE@
ht=P\E
/* R'}95S<
**Utility.java ~1 ~Xfo>
*/ S?ujRp
package NetFox; 7%MbhlN.
DC+b=IOz
t23'x0l
public class Utility { ^03j8Pc-c
2f>PO +4S{
>&,[H:Z
public Utility() ,](:<A)W&
{ _;1}x%4v
>j*;vG5T
WIr2{+#
} 'G&{GVbXY
r%@Lej5+
//线程睡眠 \f:z+F!6R
public static void sleep(int nSecond) 7ZxaPkIu&%
{ urBc=3Rz
try{ rH8@69,B
Thread.sleep(nSecond); B9R(&<4
} ^qGb%! l
catch(Exception e) kDvc" ,SD#
{ 0NDftcB]
e.printStackTrace (); *\}}Bv+9
} mLh kI!4[
} dS2G}L^L
hR#-u1C
//日志 F&RgT1*
public static void log(String sMsg) L<^j"!0
{ = ?D(g
System.err.println(sMsg); tVuWVJ4M
} _"@CGXu
`x8J
xu5ia|gYz7
public static void log(int sMsg) NLS"eDm
{ x5}'7,A
System.err.println(sMsg); %`MQmXgM
} VKp*9%9
} sm,VYYs
4y:]DC"
kOOGw:/
/* -l~Z0U>^
**TestMethod.java Vj<:GRNQ,d
*/ e^p +1-B
package NetFox; N|N3x7=gs
MP Z3D9
5 @U<I
public class TestMethod { 3E3U /K
sUZX }
[^CV>RuO
public TestMethod() !oPq?lW9
{ ///xx/weblogic60b2_win.exe N`iwC!
try{ PZxAH9 S?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <+MyZM(z>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]i(-I <`
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8Jf.ECQT
fileFetch.start(); 9.'h^#C
} [(Xy.L7x
catch(Exception e){e.printStackTrace ();} 'c2W}$q
De7Ts
=4V&*go*\
} ZkL8e
]]7mlQ
O[tvR:Nh
public static void main(String[] args) f-DL:@crU
{ P-F)%T[
new TestMethod(); 3LDS Z1f
} --;@2:lg{
} H]Hv;fcC
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