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)); 9aKt (g6
} R\^XF8n6/
for(int i=0;i<nEndPos.length-1;i++) ml\2%07
{ H%^j yGS
nEndPos = nStartPos[i+1]; c$AwJhl^]
} 3Sh#7"K3
nEndPos[nEndPos.length-1] = nFileLength; aZBb@~Y
} 4b<>gpQ
} R^ &nBwp
f zsD
+x_9IvaW&?
//启动子线程 29~Bu5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2Pz)vnV"
for(int i=0;i<nStartPos.length;i++) NU{`eM
{ N"Mw1R4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ux=0N]lc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A$;"9F@
nStartPos,nEndPos,i); %IhUQ6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *!-J"h
fileSplitterFetch.start(); 9W+RUh^W
} KE*8Y4#9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9?L,DThQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9Atnnx]n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", NR|t~C+
nEndPos = " + nFileLength); /@`kM'1:
// fileSplitterFetch[nPos.length-1].start(); sBV})8]KM
Z@d(0 z
B>XfsZS
//等待子线程结束 V9cKl[
//int count = 0; =}^J6+TVL
//是否结束while循环 4ht+u
boolean breakWhile = false; RI</T3%~
+q-/~G'
{j!+\neL
while(!bStop) qrxn%#\XP
{ /lqVMlz\77
write_nPos(); j|X>:!4r
Utility.sleep(500); Exu>%
breakWhile = true; zc#$hIi
DSX.84
\I[50eh|
for(int i=0;i<nStartPos.length;i++) .QVZ!
{ "B"Yfg[
if(!fileSplitterFetch.bDownOver) ( {}Z '
{ *%;+3SV
breakWhile = false; RwyRPc_
break; `Eq~W@';Q0
} MeMSF8zSQ
} f tE2@}
if(breakWhile) Ptj[9R
break; rmh 1.W
{M&Vh]
"2 "gTS
//count++; ;(I')[R"
//if(count>4) EnD}|9
// siteStop(); .{ +Obi
} KYN{Dh]-}
r< ~pSj
@&fAR2
System.err.println("文件下载结束！"); ?Q#yf8
} Q-7C'|
catch(Exception e){e.printStackTrace ();} j,@@[{tu
} LUN"p#1
f9FEH7S68
Fh0cOp(
//获得文件长度 waRK$/b (
public long getFileSize() ^Pp2T
{ S%{^@L+V
int nFileLength = -1; 7 S6@[-E
try{ &upM,Jsr*
URL url = new URL(siteInfoBean.getSSiteURL()); CYFi_6MFl
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /t"FZ#
httpConnection.setRequestProperty("User-Agent","NetFox"); O4lHR6M2
vn"+x_
i0/RvrLc
int responseCode=httpConnection.getResponseCode(); Pua|Z x
if(responseCode>=400) {>rGe#Vu
{ wR]jJbF
processErrorCode(responseCode); ?CU6RC n
return -2; //-2 represent access is error ?=#vp /
} o +KDK{MD
yMVlTO
#|R#/Yc@Bv
String sHeader; HmQ.'
qGVf!R
+p"}F PIK
for(int i=1;;i++) mJN*DP{
{ H.=S08c3kA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g*]/HS>e<G
//Utility.log(in.readLine()); ;:DDz
sHeader=httpConnection.getHeaderFieldKey(i); QMAineO
if(sHeader!=null) 2/F";tc\'
{ i&_&4
if(sHeader.equals("Content-Length")) TG^?J`
{ SR8)4:aKW
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q!*}^W
break; |S0nR<x-M
} 1~aP)q
} o4PJ9x5R!
else ~4^~w#R
break; n> tru L
} [~&yLccN
} ~OSgpM#O!T
catch(IOException e){e.printStackTrace ();} b<bj5m4fz>
catch(Exception e){e.printStackTrace ();} [Rxbb+,U
p'f8?jt
7H!/et?S,
Utility.log(nFileLength); Q/zlU@
;eY.4/*R
!> 2kH
return nFileLength; E>I\m!ue
} )Bw}T
rZ#ZY
J1UG},-h
//保存下载信息（文件指针位置） 50jZu'z:
private void write_nPos() )Gm,%[?2C
{ $~c wB
try{ scQnL'\
output = new DataOutputStream(new FileOutputStream(tmpFile)); '^!#*O
output.writeInt(nStartPos.length); RzOcz=A}
for(int i=0;i<nStartPos.length;i++) tN1xZW:
{ Nbvs_>N
// output.writeLong(nPos); .$"13"
output.writeLong(fileSplitterFetch.nStartPos); KBOp}MEz
output.writeLong(fileSplitterFetch.nEndPos); h"3Mj*s
} N(Sc!rX
output.close(); +oevNM
} \`U=pZJ
catch(IOException e){e.printStackTrace ();} XT%\Ce!
catch(Exception e){e.printStackTrace ();} 6"YcM:5~
} pt$\pQ
nr]:Y3KyxX
sOqT*gwr:
//读取保存的下载信息（文件指针位置） (|9t+KP
private void read_nPos() G$mAyK:
{ /P%OXn$i/
try{ 5_7y1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Aw$+Ew[8 2
int nCount = input.readInt(); [jEZ5]%
nStartPos = new long[nCount]; iu.v8I;<
nEndPos = new long[nCount]; c]%~X&Tg`
for(int i=0;i<nStartPos.length;i++) w<&R|= 93
{ K;Fs5|gFU
nStartPos = input.readLong(); A@<a')#>)
nEndPos = input.readLong(); ?Gqq]ozm
} z3Zo64V~7
input.close(); 38#Zlcf
} 8_Nyy/K#F
catch(IOException e){e.printStackTrace ();} \@B'f
catch(Exception e){e.printStackTrace ();} G_]zymXQ
} _)kTlX:,
U!i1~)s
]_(J8v
private void processErrorCode(int nErrorCode) %zz,qs)Eu
{ x/dyb.
System.err.println("Error Code : " + nErrorCode); 35%\"Y?
} )_olJCdaP^
~JQ6V?fucD
p|+TgOYOc
//停止文件下载 aqEmF
public void siteStop() {/}%[cY=
{ D/YMovH%
bStop = true; i_e%HG
for(int i=0;i<nStartPos.length;i++) yu>)[|-
fileSplitterFetch.splitterStop(); oJ?,X^~_
PH$C."Vv
U'aJCM
} 19b@QgfWpb
} es^@C9qt
//负责部分文件的抓取 QpD-%gN
**FileSplitterFetch.java jS ?#c+9
*/ 0[])wl
package NetFox; V+5av Z}
xn=#4:f
T5Iz{Ha
import java.io.*; p1UYkmx[
import java.net.*; B~B,L*kC2
0bG#'.-
6Ts[NXa
public class FileSplitterFetch extends Thread { />n!2'!
Ggry,3X3
JNv@MJb}
String sURL; //File URL "`NAg
long nStartPos; //File Snippet Start Position ]P/i}R:
long nEndPos; //File Snippet End Position #>M^BOR8
int nThreadID; //Thread's ID K7X*N
boolean bDownOver = false; //Downing is over 2m^qXE$
boolean bStop = false; //Stop identical eLIZ<zzW0}
FileAccessI fileAccessI = null; //File Access interface X-*LA*xbN
fjCFJ_
d$^@$E2f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *ze,X~8-
{ V|G*9^Y
this.sURL = sURL; UD=[::##
this.nStartPos = nStart; qP0UcG
this.nEndPos = nEnd; D"gv:RojD
nThreadID = id; C8W_f( i~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 OS-k_l L
} f0879(,i
U(gYx@
(&SPMhs_|(
public void run() RzU9]e
{ +Sc2'z>R
while(nStartPos < nEndPos && !bStop) NL,6<ZOon,
{ ^5Zka!'X2Z
.'>d7
7g$*K0m`
try{ Y-lwS-Ii
URL url = new URL(sURL); OLo?=1&;;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^WF_IH&
httpConnection.setRequestProperty("User-Agent","NetFox"); aLl=L_
String sProperty = "bytes="+nStartPos+"-"; %l,CJd5
httpConnection.setRequestProperty("RANGE",sProperty); 7K ~)7U
Utility.log(sProperty); pk`5RDBu
6LrI,d
*R}p9;dpO
InputStream input = httpConnection.getInputStream(); 31\mF\{V
//logResponseHead(httpConnection); Z;S)GUG^
G5%k.IRz
_0BQnzC=
byte[] b = new byte[1024]; jn`5{ ]D
int nRead; #"8'y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z%BX^b$Hj
{ >;lrH&
nStartPos += fileAccessI.write(b,0,nRead); -24ccN;
//if(nThreadID == 1) P_5G'[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Cn0s?3Fm
} -/ G#ls|?
`n@;%*6/
5g.w"0MkY
Utility.log("Thread " + nThreadID + " is over!"); qHgzgS7a
bDownOver = true; Kn1T2WSAg
//nPos = fileAccessI.write (b,0,nRead); `6RccEm
} TqSjL{l%
catch(Exception e){e.printStackTrace ();} X#Ob^E%J
} v,Zoy|Lu
} [kTckZv
g}S%D(~
f:t j
//打印回应的头信息 6q8PLyIp
public void logResponseHead(HttpURLConnection con) r9*6=*J|
{ YeVo=hYH@
for(int i=1;;i++) EEMRy
{ E62_k 0q
String header=con.getHeaderFieldKey(i); ;O|u`fAqT
if(header!=null) Rn`DUYg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9R">l5u
Utility.log(header+" : "+con.getHeaderField(header)); 8 &v)Vi-
else &O#1*y Z
break; RP^vx`9h
} QyY<Zi;6
} sgnc$x"
_8ks`O#}
nN^lY=3
public void splitterStop() unNN&m#@
{ NB5lxaL
bStop = true; %%#bTyF
} <Ql2+ev6
24 .'+3
Jz*A!Li
} cj^hwtx
u{w,y.l1h
*K& $9fah
/* F(ZczwvR
**FileAccess.java >^IUS8v
*//文件访问(定位，写) Lxv6\3I+
package NetFox; {;m|\652B
import java.io.*; of GoaH*h
52NI{"
LM 1Vsh<
public class FileAccessI implements Serializable{ ;JMmr-@
2<@g *
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X4!Jj*
RandomAccessFile oSavedFile; ` @lNt}
long nPos; :6Tv4ZUvcG
o\PHs4Ws'7
o q6^
public FileAccessI() throws IOException 4)>S3Yr
{ xJnN95`R@
this("",0); ;.rY`<|
} JStEOQF4
^.
$pt~?ZZ3-
public FileAccessI(String sName,long nPos) throws IOException mB6%. "
{ GctV
oSavedFile = new RandomAccessFile(sName,"rw"); OEX\]!3_Fm
this.nPos = nPos; LPZ\T}<l
oSavedFile.seek(nPos); =6f)sZpPh
} 0P!Fci/t
/"8|26
/{/mwS"W
public synchronized int write(byte[] b,int nStart,int nLen) !N_eZPU.v
{ US"UkY-\
int n = -1; Pp_? z0M
try{ Ra6}<o
oSavedFile.write(b,nStart,nLen); rZ)7(0BBs
n = nLen; )D)4=LJ
} {t.S_|IE
catch(IOException e) RTDplv; ]
{ A0,e3gb
e.printStackTrace (); _ b</ ::Tp
} hs:iyr]@9
ie>mOsz
8J- ?bo
return n; Z6Z/Y()4Tl
} }W(t>>
.<xD'54
yq<W+b/
} P_H_\KsH*(
lDF7~N9J_
g:!R't?
/* e\f\CMb
**SiteInfoBean.java e.#,9
*/ (d*||"
package NetFox; QC&,C}t,
WS?Y8~+{5
?AQA>D#W
public class SiteInfoBean { ts("(zI1E
^R)]_
2$VSH&
private String sSiteURL; //Site's URL feeHXKD|
private String sFilePath; //Saved File's Path U!K#g_}
private String sFileName; //Saved File's Name QUfF>,[sv
private int nSplitter; //Count of Splited Downloading File W7@Vma`
%`\Qtsape
?^^TR/
public SiteInfoBean() uq7/G|
{//nSplitter的缺省值为5 #l.s>B4
//default value of nSplitter is 5 OECVExb@eH
this("","","",5); yu>;m.e_
} J!dv"Ww"
~2yhZ
Fu\#:+5\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -V[!qI
{ Tj\hAcD
sSiteURL= sURL; Fg}t{e]3a
sFilePath = sPath; ]scr@e
sFileName = sName; O*x~a;?G
this.nSplitter = nSpiltter; + Okw+v
J4z&J SY
I3izLi
} +"JWsD(C(
:f7vGO"t
iP:^nt?
public String getSSiteURL() :_nGh]%
{ ~"4Cz27
return sSiteURL; %M`zkA2]J
} Asq&Z$bB_
B(6*U~Kn%
.|TF /b]
public void setSSiteURL(String value) ZP&iy$<L
{ /TIt-c
sSiteURL = value; Z:V<P,N
} +qqCk
"{3|(Qs
PI,2b(`h_
public String getSFilePath() Ml{4)%~Y7f
{ z(2G"}
return sFilePath; ~Ga{=OM??
} A`>^A]%
`Hv"^o
!YlEXaS
public void setSFilePath(String value) x")Bmw$
{ /OMgj7olD
sFilePath = value; aD6!x3c/
} A{T>Aac
E8<,j})*
H`Zg-j`
public String getSFileName() *"6A>:rQs
{ =4&"fZ"v
return sFileName; ]@}hyM[D;
} +%~me?
sEZ2DnDI
|?MD>Pez
public void setSFileName(String value) #SjCKQ~
{ De>,i%`Q,D
sFileName = value; -lq`EB+
} 0m\( @2E
6lkCLH
'P4V_VMK
public int getNSplitter() 9i{(GO
{ f9IqcCSW
return nSplitter; v|(N
} osLEH?iKW
MU:v& sk
hgwS_L
public void setNSplitter(int nCount) HW'I$ .
{ EQM[!g^a
nSplitter = nCount; 98uMD
} w_LkS/
} #G?",,&dM
#T`1Z"h<
_G/uDP%
/* +@7c:CAy(
**Utility.java B)0;gWK
*/ +>c%I&h}`
package NetFox; +#A~O4%t
Q7UQwAN'
3hzz*9/n
public class Utility { DiZv sc
#!_ViG )2^
="Azg8W
public Utility() <A`SC;k\u
{ r?pFc3~N
Z-" NLwt[
iuM ,aF
} f3h]t0M
2n#H%&^?a
//线程睡眠 }/IP\1bG
public static void sleep(int nSecond) oJ#;XR
{ y`/:E<fVk
try{ :x^e T
Thread.sleep(nSecond); e"p){)*$
} ec*Ni|`Z'
catch(Exception e) t~qAA\p}o
{ IEI&PRD
e.printStackTrace (); C*t0`3g d
} cA| n*A-j<
} 3#\C!T0y
c{x:'@%/s'
//日志 =Pp-9<&S
public static void log(String sMsg) 60D6UW
{ &b-&0rTqz
System.err.println(sMsg); !2/o]_K@+
} zU4*FXt
,XN4Iy#BZl
vo~Qo;m
public static void log(int sMsg) gzlRK^5
{ Wrt5eYy
System.err.println(sMsg); KmqgP`Cu
} d*@K5?O.
} ,.;{J|4P
O >@Q>Z8W?
^.*zBrFx
/* i.FdZN{
**TestMethod.java xsvJjs;=
*/ V,?])=Ax
package NetFox; DV*e.Y>
GK3cQw
:01B)~^
public class TestMethod { @Yw42`>!s
8zjJshE/
_5OxESE
public TestMethod() bJeF1LjS
{ ///xx/weblogic60b2_win.exe Sg\+al7
try{ SxkY ;^-U
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &7{yk$]*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zIr-Rx'dL^
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5)->.*G*
fileFetch.start(); B@' OUcUR
} "K;""]#wg0
catch(Exception e){e.printStackTrace ();} /U6ry'
j|[>f
PMQlJ&
} e YiqTWn:
Ypinbej
{ / ,?3
public static void main(String[] args) )t2eg1a:
{ c;n\HYk
new TestMethod(); Lg-!,Y
} Q*e\I8R}
} ajf(Ii\/
点击下载更多相关资料