http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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^F^|WT$
} mQmn&:R
for(int i=0;i<nEndPos.length-1;i++) !8q+W`{
{ ^,L vQW4
nEndPos = nStartPos[i+1]; H"|xG;cf
} FLI\SF<
nEndPos[nEndPos.length-1] = nFileLength; L,*KgLG
} 6QsH?!bu
} 3L$_OXx
-%]O-'
IYm~pXg^0
//启动子线程 %{\|/#>:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; B .p&,K
for(int i=0;i<nStartPos.length;i++) l6Hu(.Ls;j
{ (~F{c0\C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), O5HK2Xg,C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V5y8VT=I
nStartPos,nEndPos,i); yjZ]_.
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p<1z!`!P
fileSplitterFetch.start(); ,1'9l)zP
} }Z T{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $:M*$r^u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ta]B9&c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SVsLu2tVY
nEndPos = " + nFileLength); /0Q=}:d
// fileSplitterFetch[nPos.length-1].start(); y,&UST
C3kxw1*
h^klP:Q
//等待子线程结束 a.+2h%b
//int count = 0; 0z) 8i P
//是否结束while循环 O)nLV~X
boolean breakWhile = false; w=EUwt
aEr<(x!|"
h8;B+#f`
while(!bStop) 6~8A$:
{ * z|i{=W F
write_nPos(); Wx#((T
Utility.sleep(500); fUQuEh5_
breakWhile = true; q[4{Xh
^UP!y!&N
,L#Qy>MOb
for(int i=0;i<nStartPos.length;i++) <.j`n
{ OE87&Cl"{t
if(!fileSplitterFetch.bDownOver) '>[l1<d!G
{ K;jV"R<9
breakWhile = false; WF0%zxg]
break; ,Y&LlB 2
} /(C?3}}L
} ^)ouL25Z*2
if(breakWhile) 7Q,9j.
break; &7* |rshZ
CJB
V4cCu~(3;~
//count++; [+0rlmB
//if(count>4) Va^Y3/
// siteStop(); 32!jF}qpD
} vK2sj1Hzr
~l$u~:4Ob
:uhU<H<,f
System.err.println("文件下载结束！"); [.\uHt
} Df;EemCh
catch(Exception e){e.printStackTrace ();} IC&xL9
} <p"[jC2zF;
ylm*a74-X
i oX [g
//获得文件长度 Y<('G5A
public long getFileSize() 6<sd6SM
{ "Y(stRa
int nFileLength = -1; yl|?+
try{ MhMY"bx8
URL url = new URL(siteInfoBean.getSSiteURL()); )cA#2mlS'1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); dQ6:c7hp>D
httpConnection.setRequestProperty("User-Agent","NetFox"); |J:n'}
4;anoqiG\
M@$}Og
int responseCode=httpConnection.getResponseCode(); Il(p!l<Xz#
if(responseCode>=400) om%L>zfB
{ _`yd"0Ux
processErrorCode(responseCode); pME17 af
return -2; //-2 represent access is error _ndc^OG
} y]|Hrx
V<~.:G$3H
shjc`Tqm
String sHeader; 5\RTy}w3x
L:$kd `v[
KT1/PWa
for(int i=1;;i++) RlH|G
{ uC{qaMQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JCoDe.
//Utility.log(in.readLine()); X0<qG
sHeader=httpConnection.getHeaderFieldKey(i); P:GAJ->;]>
if(sHeader!=null) *^j'G^n
{ Oax*3TD
if(sHeader.equals("Content-Length")) #+)AIf
{ 2=Sv#
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V~j:!=b%v
break; ,&>LBdG`
} %LBa;M
} VO#x+u]/
else D$C>ZF
break; +"8 [E~Bih
} )!+M\fT
} P%?|V_m
catch(IOException e){e.printStackTrace ();} [ kI|Thx
catch(Exception e){e.printStackTrace ();} 4.7YIM
npsDy&
G-`4TQ
Utility.log(nFileLength); X}T/6zk
(Fc\*Vn
2$=U#!OtU
return nFileLength; *v1M^grKd
} 2aQR#lcv
yW::`
H CKD0xx
//保存下载信息（文件指针位置） ;Du+C%
private void write_nPos() uSnG=tB
{ 0p6
try{ t%@sz
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5`su^
output.writeInt(nStartPos.length); ,;3#}OGg
for(int i=0;i<nStartPos.length;i++) >uVo'S.
{ ~s.~X5
// output.writeLong(nPos); 0#\K9|.
output.writeLong(fileSplitterFetch.nStartPos); i?+ZrAx>
output.writeLong(fileSplitterFetch.nEndPos); ?:@13wm
} JbT+w\o
output.close(); #2*l"3.$.R
} pq8XCOllXx
catch(IOException e){e.printStackTrace ();} ;U7o)A;
catch(Exception e){e.printStackTrace ();} k'O^HMAn!
} VaYL#\;c<
<2b&AF{En
r6 k/QZT
//读取保存的下载信息（文件指针位置） O&DkB*-
private void read_nPos() iBCZx>![;
{ Gn*cphb
try{ pib i#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %6A."sePO
int nCount = input.readInt(); JQ5E;8J>
nStartPos = new long[nCount]; CC{*'p6
nEndPos = new long[nCount]; kV>[$6
for(int i=0;i<nStartPos.length;i++) X`-7: !+
{ MNC=r?
nStartPos = input.readLong(); m Acny$u
nEndPos = input.readLong(); UZcsMMKH
} w'Y(doY,
input.close(); >"LHr&;m&h
} ^HS;\8Xvb
catch(IOException e){e.printStackTrace ();} :P,g,
catch(Exception e){e.printStackTrace ();} U;SReWqU
} 0L->e(Vf7u
36]pE<
}~W:3A{7;
private void processErrorCode(int nErrorCode) UA>3,|gV1
{ i}&&rr
System.err.println("Error Code : " + nErrorCode); \"]KF8c^_
} ALcin))+B
\<e?
@;\2 PD
//停止文件下载 2@TgeV0Y[
public void siteStop() hc"l^a!7ic
{ AN193o
bStop = true; { XI0KiE
for(int i=0;i<nStartPos.length;i++) X`/GiYTu
fileSplitterFetch.splitterStop(); aPU.fER
>(EC.ke
?<F=*eS
} .[8! E_
} "0*yD[2
//负责部分文件的抓取 !sknO53`H`
**FileSplitterFetch.java D.[h`Hkc
*/ 9Wu c1#
package NetFox; pyHU+B
+ 6noQYe
Q!9
import java.io.*; Cs:?9G
import java.net.*; 8 x=J&d
1iA0+Ex(j
Fb2,2Px
public class FileSplitterFetch extends Thread { 3!l+)g
lw\+!}8(
\eF_Xk[
String sURL; //File URL W8blHw"
long nStartPos; //File Snippet Start Position `}r)0,Z}3
long nEndPos; //File Snippet End Position L/J1;
int nThreadID; //Thread's ID 5taR[ukM
boolean bDownOver = false; //Downing is over }nEa9h
boolean bStop = false; //Stop identical MQc<AfW3/
FileAccessI fileAccessI = null; //File Access interface N_:H kI6
*|gY7Av*
(6}[y\a+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException enC/@){~
{ &9+]{jXF
this.sURL = sURL; ZZs@P#]
this.nStartPos = nStart; hqXp>.W
this.nEndPos = nEnd; g2LY~
nThreadID = id; lQS(\}N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^cUmLzM
} =l)D$l
*&vlfH
@:dn\{Zsea
public void run() k!Ym<RD%N
{ c;X%Ar
while(nStartPos < nEndPos && !bStop) E,kDy:
{ Y9/`w@"v
|D% O`[k+
$#z-b@s=B
try{ bmOK8
URL url = new URL(sURL); f};RtRo2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _2-fH
httpConnection.setRequestProperty("User-Agent","NetFox"); *5QN:
String sProperty = "bytes="+nStartPos+"-"; bcR";cE
httpConnection.setRequestProperty("RANGE",sProperty); adcH3rV
Utility.log(sProperty); x/pX?k
B_uhNLd
Aaw]=8 OI
InputStream input = httpConnection.getInputStream(); ~hZr1hT6L
//logResponseHead(httpConnection); m >Rdsn~l
A_!N,<-
%jE0Z4\
byte[] b = new byte[1024]; !+k);;.+
int nRead; NR>&1aRbyb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SeV`RUO
{ =dT #x
nStartPos += fileAccessI.write(b,0,nRead); }6'%p Bd
//if(nThreadID == 1) +F?}<P_v
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Bq5-L}z
} ,Y&7` m
[59g]')
j%U'mGx
Utility.log("Thread " + nThreadID + " is over!"); ynZp|'b?<
bDownOver = true; 1!%T<!A.
//nPos = fileAccessI.write (b,0,nRead); ]+k]Gbty6
} Yu}[RXC(=
catch(Exception e){e.printStackTrace ();} 4C#r=Uw`
} hS 9^Bi
} pJ3-f k"i
zH13~\
6Y%{ YQ}s|
//打印回应的头信息 2@6Qifxd@
public void logResponseHead(HttpURLConnection con) Ueu~803~
{ N79?s)l:K
for(int i=1;;i++) 3Q#Tut
{ Ez/>3:;
String header=con.getHeaderFieldKey(i); i*]$_\yl"
if(header!=null) dEI]|i r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hcqg94R#_
Utility.log(header+" : "+con.getHeaderField(header)); cCx_tGR"
else {.j030Q
break; ]IclA6
} vn+~P9SHQ
} ~<Z7\yS)
.T1n"TfsGO
)GKY#O09x9
public void splitterStop() wpI"kk_@@
{ czLY+I;V3
bStop = true; pkE4"M!3=
} B/_~j_n$m
UL.YDU)
AZE
} DC~1}|B"
K8JshFIe
5^97#;Q;J"
/* ,_UTeW6M
**FileAccess.java c :2w(BVi
*//文件访问(定位，写) ":_~(?1+
package NetFox; )zydD=,bu
import java.io.*; \>tx:;D3
ja4zLf(<
)*L=$0R
public class FileAccessI implements Serializable{ #0f6X,3
c 'rn8Jo}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z[qi~&7:v
RandomAccessFile oSavedFile; O|nLIfT
long nPos; )!lx'>0>
pupt__NZ)n
FOAXm4"
public FileAccessI() throws IOException 4$y P_3
{ Yy{(XBJ~%t
this("",0); KRM:h`+-.-
} S"/-)_{
Os/?iGlD*E
n}dLfg*
public FileAccessI(String sName,long nPos) throws IOException $T6+6<
{ } 4ZWAzH
oSavedFile = new RandomAccessFile(sName,"rw"); qi['~((
this.nPos = nPos; &a+=@Z)kf
oSavedFile.seek(nPos); B"rO
} C^fn[plL
+} y"S-
RB9ZaL\
public synchronized int write(byte[] b,int nStart,int nLen) $>zqCi2tB<
{ 61}eB/;7
int n = -1; tpa<)\7KJ
try{ XG E.*aI
oSavedFile.write(b,nStart,nLen); :W9a t
n = nLen; Ri>ZupQ6
} bs'hA@r
catch(IOException e) XM)
{ 5FE&
e.printStackTrace (); VsDY,=Ww
} 0$_WIk
h!7Lvh`o
hGcu(kAC,
return n; s &f\gp1
} w8bvqTQ
r&_e3#]*
E"7[|-`e6
} /z)Nz2W
Ab8Ke|fA
CY\D.Eow
/* <cFj-Ys(T
**SiteInfoBean.java M6j~`KSE
*/ z<_a4ffR
package NetFox; 8v)iOPmDC
A@eR~Kp ^
30O7u3Zrb
public class SiteInfoBean { *6G@8TIh
"|BSGV!8
xkQT#K=i
private String sSiteURL; //Site's URL ~sdM~9@ '
private String sFilePath; //Saved File's Path iZ4"@G:,
private String sFileName; //Saved File's Name Q)=2%X
private int nSplitter; //Count of Splited Downloading File aK8s0G!z?5
aoBiN_
xX@9wNYD
public SiteInfoBean() FQ0PXYh
{//nSplitter的缺省值为5 @}s EP&$
//default value of nSplitter is 5 dsg-;*%
this("","","",5); /CUBs!
} Bh&dV%'
a+j"8tHu$
R7A:K]iJ5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5n[''#D
{ k\r^GB
sSiteURL= sURL; lx7]rkWo|a
sFilePath = sPath; e|q~t {=9S
sFileName = sName; ornU8H`
this.nSplitter = nSpiltter; V{fG~19
Hzz v 6k
X6BOB?
} j_h0hm]
%/d1x
s{*bFA Z1F
public String getSSiteURL() Z)f?X
{ {&a6<y#-
return sSiteURL; ^b4i9n,t1
} D=SjCmG
T:".{h-i
211V'|a_>
public void setSSiteURL(String value) -`NzBuV$2,
{ =ui3I_*)
sSiteURL = value; 9ji`.&#
} =mSu^q(l
'hFL`F*
;0`IFtz
public String getSFilePath() >I',%v\?@
{ LQR^lD+_=
return sFilePath; HBZ6Pj
} dkeMiLm
Ko)f:=Qo
mW~*GD~r
public void setSFilePath(String value) s~ou$!|
{ 6 $`l
sFilePath = value; .@ZrmO o]]
} sLWVgD
HA[7)T N1E
< FY%QB)h
public String getSFileName() 0\,!
{ 4K 8(H9(
return sFileName; *U$%mZS]1
} ]^Xj!01~
T=RabKVYP
qFl|q0\ A
public void setSFileName(String value) M%g2UP
{ E^0a; |B[
sFileName = value; =\mJ5v"hA
} TM|PwY
?<S fhjU
QMy1!:Z&!
public int getNSplitter() 4$81ilBcL
{ :98:U~d1
return nSplitter; 6Kw?
} +N'&6z0Wf
Xtloyph
d\zUtcJwC
public void setNSplitter(int nCount) KT17I&:
{ |9p0"#4u
nSplitter = nCount; CSz+cS
} :F9Oj1lM%
} bkz/V/Y
bcT'!:
X<5&R{oZ
/* jeB"j
**Utility.java qJ .XI
*/ nB0KDt_
package NetFox; 5"(FilM
abCxB^5VL
CNhLp#
public class Utility { Z>l<.T"t'
ZAn9A>5_
*_P'>V#p
public Utility() J#q^CWN3R
{ ,gM:s}l!dJ
YQWq*o^:
,6o tm
} @sW!g;\T
:G]t=vr1
//线程睡眠 s%8,'3&
public static void sleep(int nSecond) 8'NT_NPNb
{ fsWIz1K
try{ nrX+ '
Thread.sleep(nSecond); i r'C(zD=
} \(&&ed:
catch(Exception e) cmAdQ)(Kzd
{ Z~}9^(qc
e.printStackTrace (); 9M;Y$Z
} M?o_J4
} `~=NBN=tiL
eKo=g|D
//日志 ;lSsy
public static void log(String sMsg) L)1\=[Ov
{ `C$QR 8
System.err.println(sMsg); -F 9xPw
} h0HK~S#xBv
~|N,{GaL
`U|zNizO
public static void log(int sMsg) 5:#|Op N
{ 9MQjSNYzo
System.err.println(sMsg); {+[Ex2b$
} j(}pUV B
} ~Nf|,{[(5
Mz+vT0
)vpYVr-
/* wQ~]VVRN
**TestMethod.java rq Uk_|Xa
*/ /0$405
package NetFox; 8TK*VOf`
gvD*^
/k(wb4Hv
public class TestMethod { nLC5FA7<
c=QN!n:
-@Urq>^v T
public TestMethod() Jr= fc*f
{ ///xx/weblogic60b2_win.exe [LUqF?K&
try{ T LF'7ufq
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Le{.B@2-"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q04 `+Vr
SiteFileFetch fileFetch = new SiteFileFetch(bean); qJ<l$Ig
fileFetch.start(); wp5H|ctl
} dV16'
catch(Exception e){e.printStackTrace ();} SLUQFoz}
/Ahh6=qQY
ledr[)
} |`s:&<W+kp
rvK%m_r
8j :=D!S
public static void main(String[] args) K V
{ v(=0hY9 O
new TestMethod(); Oamz>Hplu
} <G`1(,g
} }' sW[?ik
点击下载更多相关资料