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/sqOhg
} 5p{tt;9[
for(int i=0;i<nEndPos.length-1;i++) $t</{]iX
{ !c`Q?aGV)
nEndPos = nStartPos[i+1]; zsRN\U
} VF==F_l
nEndPos[nEndPos.length-1] = nFileLength; Q+ST8
} 8UL:C?eY
} .y[K =p3
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k~?}z.g(
//启动子线程 yZ)ScB^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s9GPDfZ
for(int i=0;i<nStartPos.length;i++) +ow ^xiD
{ qP<,"9!I
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x!.VWGtb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fAUsJ[
nStartPos,nEndPos,i); x?<5=,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q6W)rJ[|
fileSplitterFetch.start(); 'IW+"o
} $-AvH(@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SCH![Amq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); t@JPnA7~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G =4y!y
nEndPos = " + nFileLength); ~D=@4(f8|
// fileSplitterFetch[nPos.length-1].start(); dO//
yEqmB4^-
yaR;
//等待子线程结束 aQmL=9
//int count = 0; I!<v$
//是否结束while循环 Qy/bzO
boolean breakWhile = false; c_a$g
9G8QzIac
EH "g`r
while(!bStop) M>J ADt_]
{ o%QQ7S3P
write_nPos(); d$,i?d,
Utility.sleep(500); -pGt;
breakWhile = true; *(MvNN*
*_wef/==
Q%xY/xH]
for(int i=0;i<nStartPos.length;i++) )|a9Z~#x
{ 9c7}-Go
if(!fileSplitterFetch.bDownOver) udZ: OU<
{ hw'2q9J|
breakWhile = false; E$>e< T
break; {G0)mp,
} bg*{1^
} rWs5s!l,
if(breakWhile) KJ)&(Yx
break; FVmg&[ .
C|J1x4sb@
85{vz|(':
//count++; QMxz@HGa|
//if(count>4) a*[\edcHU
// siteStop(); ed*AU,^@v
} X[~CLKH(
g[jZ A[[
V6{xX0'b*m
System.err.println("文件下载结束！"); =|%T E
} W7o/
catch(Exception e){e.printStackTrace ();} {|E7N"Qzg
} ui{_w @o
{LD8ie|x1`
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//获得文件长度 VT7NWTJ,
public long getFileSize() a!K;8#xc
{ \-0`%k"&
int nFileLength = -1; rw2|1_AF
try{ DS2$w9!
URL url = new URL(siteInfoBean.getSSiteURL()); JrAc]=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @#tSx
httpConnection.setRequestProperty("User-Agent","NetFox"); 9.=#4OH/
8W>l(w9M
dSZ#,Ea"
int responseCode=httpConnection.getResponseCode(); //@=Q!MW
if(responseCode>=400) m6cW
{ [AzN&yACE
processErrorCode(responseCode); +3>4 ?,^g
return -2; //-2 represent access is error ;LE @Ezx
} fdG.=7`
6I#DlAU@v
$IT9@}*{
String sHeader; ?63JQ.;
uP]o39b;V
rfi`Bp
for(int i=1;;i++) FO=1P7
{ uCfp+
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;/T-rVND
//Utility.log(in.readLine()); ,-Nk-g
sHeader=httpConnection.getHeaderFieldKey(i); <R>ZG"m{
if(sHeader!=null) BD-=y
{ K:@=W1
if(sHeader.equals("Content-Length")) OF/)-}!
{ q)b?X ^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QZox3LM1&.
break; [9_ (+E[}
} Gnt!!1_8L
} uP2a\C,$
else K>6k@okO
break; s*~o%emw
} 3]es$Jy
} Fd&!-`T?
catch(IOException e){e.printStackTrace ();} PZJ 4:h
catch(Exception e){e.printStackTrace ();} F:S>\wG,
mm-UQ\h
"\r~,S{:
Utility.log(nFileLength); MwqT`;lb
a[g|APZz
CZRo{2!?U
return nFileLength; \Egc5{
} (v:ek_
!F#aodM1N
qjzW9yV+
//保存下载信息（文件指针位置） wP0+Xv,
private void write_nPos() Q5n :f+
{ ;S`-9}6
try{ (x0*(*A}
output = new DataOutputStream(new FileOutputStream(tmpFile)); lkg*AAR?'
output.writeInt(nStartPos.length); Z[S+L"0
for(int i=0;i<nStartPos.length;i++) hyfnIb@~}
{ PZRn6Tc
// output.writeLong(nPos); .{a2z*o
output.writeLong(fileSplitterFetch.nStartPos); bK8F |
output.writeLong(fileSplitterFetch.nEndPos); rOb"S*
} :yjK*"T|OD
output.close(); ZCFf@2&z8
} eSNSnh]'
catch(IOException e){e.printStackTrace ();} rE `}?d
catch(Exception e){e.printStackTrace ();} E0^%|Mh]b
} "IS^ajaq
jZT :-w
&MZy;Sq
//读取保存的下载信息（文件指针位置） lN>C#e<]
private void read_nPos() `Uj?PcS_
{ )NmlV99q
try{ Wo+CQH6(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S/<"RfVU#o
int nCount = input.readInt(); hdJwNmEA>
nStartPos = new long[nCount]; 'F"Y?y:!
nEndPos = new long[nCount]; UW[{d/.wC
for(int i=0;i<nStartPos.length;i++) 0/@ X!|X
{ xTFrrmxOf
nStartPos = input.readLong(); tK}p05nPhl
nEndPos = input.readLong(); k+#l;<\2
} x>,F*3d3
input.close(); ]'!xc9KGR
} l()MYuLNV
catch(IOException e){e.printStackTrace ();} apD=>O
catch(Exception e){e.printStackTrace ();} o?mXxL)
} N46$EsO!h
vd7N&c9
0$L0fhw.
private void processErrorCode(int nErrorCode) !_-sTZ
{ Z<|_+7T
System.err.println("Error Code : " + nErrorCode); Iei7!KLW
} wEnuUC4j
=ch Af=
WCmNibj
//停止文件下载 m_!vIUOz
public void siteStop() Jp3di&x
{ &M3ES}6
bStop = true; YG 5Z8@kH
for(int i=0;i<nStartPos.length;i++) 0SYf<$
fileSplitterFetch.splitterStop(); _p J_V>l
ca/o#9:N`:
yaRcBT?
} nOal7BNN
} b?]ly(
//负责部分文件的抓取 yvooM'R
**FileSplitterFetch.java "vOfAo]`
*/ `,Y[Z
package NetFox; u@Cf*VPK
2@R8P~^W
fQW_YQsb
import java.io.*; IFrb}yH
import java.net.*; GtM( Y
7}'A)C>J;
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public class FileSplitterFetch extends Thread { 33<fN:J]f
`!omzE*bk5
{nQ)4.e6
String sURL; //File URL S}w.#tyEn
long nStartPos; //File Snippet Start Position @bW[J
long nEndPos; //File Snippet End Position v-;XyVx
int nThreadID; //Thread's ID \%Ah^U)gS
boolean bDownOver = false; //Downing is over rI<nUy P?
boolean bStop = false; //Stop identical ?wLdW1&PpX
FileAccessI fileAccessI = null; //File Access interface :Dk@?o@2;C
r!.+XrYg
i,'Ka[6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O| 1f^_S/
{ xdL/0 N3
this.sURL = sURL; _[TH@fO6:
this.nStartPos = nStart; 'o/N}E!Pt
this.nEndPos = nEnd; P('t6MVlT
nThreadID = id; "s>fV9YyZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2fzKdkJhe
} %R5Com
fys5-1@-p
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public void run() XJmFJafQD
{ &gA6+b'
while(nStartPos < nEndPos && !bStop) 29Z!p2{hk
{ T,WKoB
MjQ[^%lfL
QOT)x4!)
try{ A \MfF
URL url = new URL(sURL); *bCi2mbm@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dNUR)X#e
httpConnection.setRequestProperty("User-Agent","NetFox"); oNuPP5d[]
String sProperty = "bytes="+nStartPos+"-"; PG6[lHmi
httpConnection.setRequestProperty("RANGE",sProperty); }z%OnP
Utility.log(sProperty); W&+y(Z-t
t{R5 EU
(VYR!(17
InputStream input = httpConnection.getInputStream(); 83KfM!w
//logResponseHead(httpConnection); ptV4s=G2
1z~k1usRK
r]k*7PK
byte[] b = new byte[1024]; 9W1;Kb|Z<
int nRead; 8pYyG |\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [8F \;
{ M`0(!Q}
nStartPos += fileAccessI.write(b,0,nRead); j|VXC(6P,
//if(nThreadID == 1) 8yE!7$Mj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #_.g2 Y
} 'FShNY5
5oz>1
}FPM-M3y
Utility.log("Thread " + nThreadID + " is over!"); Y 3o^Euou
bDownOver = true; {]&R8?%
//nPos = fileAccessI.write (b,0,nRead); ?VwK2w$&={
} 89zuL18V
catch(Exception e){e.printStackTrace ();} h ZoC _\
} W`#gpi)7N
} c}\ 'x5:o
jEUx q%BH
<z^SZ~G
//打印回应的头信息 +x(YG(5\w
public void logResponseHead(HttpURLConnection con) gf+o1\5t@
{ xb%/sz(4
for(int i=1;;i++) +Dv7:x7
{ [ L
String header=con.getHeaderFieldKey(i); Iq+2mQi*/k
if(header!=null) I$n+DwKcN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^>-+@+( r
Utility.log(header+" : "+con.getHeaderField(header)); Q-[3j
else a;%I\w;2
break; 5)w4)K-%
} SGt5~Txj
} O47PkP8
jQ6Xr&}
>wA+[81[
public void splitterStop() vruD U#
{ 5`"iq "5Cf
bStop = true; +6 ho)YL
} U<Vy>gIC
X1Qr_o-BR
ThtMRB)9
} 6_WmCtvF
Z%#^xCz;w>
|7y6 pz
/* [~COYjp
**FileAccess.java :WVSJ,. !
*//文件访问(定位，写) :i.t)ES
package NetFox; m;c3Z-
import java.io.*; 6Z Xu,ks}
x.ba|:5
fTcY"A,2
public class FileAccessI implements Serializable{ -OWZ6#v(
^;+[8:Kb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K!p,x;YX
RandomAccessFile oSavedFile; R }1W
long nPos; .@@an;C
$%Z3;:<Uf-
*#zS^b n
public FileAccessI() throws IOException 40u7fojg2
{ !~)90Z!
this("",0); u\f3qc,]F
} B_hPcmB
mg`j[<wp
f~q4{
public FileAccessI(String sName,long nPos) throws IOException L"^OdpOs
{ k=`$6(>Fz
oSavedFile = new RandomAccessFile(sName,"rw"); "CBRPp
this.nPos = nPos; #BsW
oSavedFile.seek(nPos); P].eAAXnP
} `kFiH*5%z
r_^)1w
Tpb"uBiXoo
public synchronized int write(byte[] b,int nStart,int nLen) E~qQai=]
{ 4^[ /=J}
int n = -1; +pz}4M`
try{ >OK#n)U`
oSavedFile.write(b,nStart,nLen); z3W3=@
n = nLen; ET.dI.R8
} <[ZI.+_Wt
catch(IOException e) =G4u#t)
{ *1$
e.printStackTrace (); P_&p=${
} nM8[
A@2Bs5F
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return n; U7h(-dV
} a~opE!|m
w^Ag]HZN
6Hk="$6K
} ~>g+2]Bn>$
-9d%+O~v6~
&?y7I Pp
/* RkA8
**SiteInfoBean.java WI&lj<*
*/ gw+eM,Yp
package NetFox; gfN2/TDC]P
epkD*7
R!6=7
public class SiteInfoBean { 6]n/+[ ks
o/^1Wm=
:^#vxdIC?
private String sSiteURL; //Site's URL )c+k_;t'+
private String sFilePath; //Saved File's Path DW>ES/B8$(
private String sFileName; //Saved File's Name [EOVw%R
private int nSplitter; //Count of Splited Downloading File @PX\{6&
2"X~ju
id?E)Jy
public SiteInfoBean() I3(d<+M
{//nSplitter的缺省值为5 !),t"Ae?>
//default value of nSplitter is 5 to`mnp9Z
this("","","",5); N 9LgU)-Jt
} uokc:D
4x=(Zw_X
~KPv7WfG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4-^[%&>}
{ 0[Eb .2I
sSiteURL= sURL; ykmv'a$-4
sFilePath = sPath; v@n_F
sFileName = sName; E oe}l
this.nSplitter = nSpiltter; uR:rO^
]C!?HQ{bsf
z:}nBCmLV
} z_&P?+"Df
S-c ^eLzQ
}`_(<H
public String getSSiteURL() 2hq\n<
{ cP rwW6
return sSiteURL; vFhz!P~
} e.8$ga{
7u|B ](FS
wk @,wOt
public void setSSiteURL(String value) [_.n$p-
{ 24B<[lSK
sSiteURL = value; iKAusWj
} !%[S49s
!Z|($21W
qINTCm j
public String getSFilePath() izuF !9
{ /{*$JF
return sFilePath; Qihdn66
} VteEDL/w
#{PmNx%M
ppN} k)m
public void setSFilePath(String value) !20XsO
{ Bp_wnd
sFilePath = value; ?obm7<
} G5Ykbw#
bRsTBp;R`I
tj5giQ3DG)
public String getSFileName() z7T0u.4Ss
{ tC)6
return sFileName; L0"~[zB]N
} (CE7j<j
|5MbAqjzC
`^6 ,kI-c
public void setSFileName(String value) /+[63=fl
{ 1@qgF
sFileName = value; +B"0{>n}F
} ;rR/5d1!
%!|O.xxRR
E^CiOTN
public int getNSplitter() ar^i|`D
{ Or+p%K}-7
return nSplitter; RE"^ )-
} cUk*C
>*1}1~uU`'
qTmD'2
public void setNSplitter(int nCount) ,hRN\Kt)p
{ $>q@SJ1q
nSplitter = nCount; !#N\b
} N#k61x
} r{K;|'d%h
(f#b7O-Wn
=RsXI&&vh
/* g0R[xOS|
**Utility.java `u_Qa
*/ [hh/1[
package NetFox; /aqEJGG>
+%0z`E\?M#
bS!\#f%9"
public class Utility { HdX2YPYn;
8%:]W^
))T>jh
public Utility() WAPhv-6
{ jNyoN1M
#&8rcu;/
7Y( 5]A9=
} Ng=ONh
@g-Tk
//线程睡眠 MMQ;mw=^]
public static void sleep(int nSecond) v~)LO2y
{ n/Dp"4H%q
try{ /-M@[p&
Thread.sleep(nSecond); ,kM)7!]N
} \}"m'(\c
catch(Exception e) 0C$vS`s&
{ 27Emm c
e.printStackTrace (); ccJM>9
} lB;FUck9
} &^.57]
z\!K<d"Xv
//日志 X[3}?,aqL
public static void log(String sMsg) L 3XB"A#
{ U5r}6D!)
System.err.println(sMsg); cj$6
} }}{Yw
1KE:[YQ1
H)(jh
public static void log(int sMsg) Ey`h1Y
{ IDFFc&
System.err.println(sMsg); pPro }@@
} 5/0j}_pP
} 1DJekiWf
NL"G2[e
)A8v];.]3
/* `BXS)xj
**TestMethod.java hZ$t$3
*/ dp5cDF}l
package NetFox; ku&k'V
HIvZQQW|
)%Iv[TB[
public class TestMethod { N_gD>6I
A#y@`}]!'
Y3U9:VB
public TestMethod() +cu^%CXT
{ ///xx/weblogic60b2_win.exe k!L@GQ
try{ \?fIt?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^A_;#vK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {8RFK4! V@
SiteFileFetch fileFetch = new SiteFileFetch(bean); B4H!5b
fileFetch.start(); g_.^O$}
} t+Bf#:
catch(Exception e){e.printStackTrace ();} 8?FueAM'
GZ#aj|
]$iqa"{
} 3lxc4@Zmd
L"+$Wc[|
[:EvTY
public static void main(String[] args) ]ZoPQUS?
{ $)~
new TestMethod(); ef"?|sn
} Dt}rR[yJ
} _=XX~^I,
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