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)); I\:(`)"r
} +JRPd.B"@
for(int i=0;i<nEndPos.length-1;i++) t{RdqAF
{ =6LF_=}
nEndPos = nStartPos[i+1]; $g!~T!p=
} !w=6>B^
nEndPos[nEndPos.length-1] = nFileLength; y9)Rl)7-:
} "qvJ-Y
} W<s5rMx
<c$K3
/$?7L(
//启动子线程 -/ h'uG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v\b@;H`
for(int i=0;i<nStartPos.length;i++) ,T\)%q
{ 5t-dvYgU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mnS F=l;;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5>*~1}0T
nStartPos,nEndPos,i); 3X A8\Mg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^=V b'g3P~
fileSplitterFetch.start(); P gK> Z,
} (n3MbVi3LU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mj9r#v3.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NoG`J$D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <m!(eLm+B
nEndPos = " + nFileLength); 47 *,
// fileSplitterFetch[nPos.length-1].start(); [Uw/;Kyh
hj|P*yKV
L>Soj|WUy(
//等待子线程结束 U|}Bk/0.
//int count = 0; [[;vZ
//是否结束while循环 ?wQaM3 |^:
boolean breakWhile = false; FF7
Ua=w;h
?RVY%s;g
while(!bStop) 6Om)e=gU/
{ nFY6K%[
write_nPos(); VQ((c:+!
Utility.sleep(500); /WWD;keP5
breakWhile = true; :Mq-4U.e
v<c@bDZ>
d0MF\yxh
for(int i=0;i<nStartPos.length;i++) .S=^)
{ qe"t0w|U?
if(!fileSplitterFetch.bDownOver) 9XSZD93L
{ us TPr
breakWhile = false; Zr U9oy&!C
break; ?*h2:a$
} i`)h~V|G
} ~i ImM|*0
if(breakWhile) r^,XpRe&M
break; ,Kw]V %xOb
+IpC
xesZ7{ o
//count++; \vQjTM-7
//if(count>4) )r^)e4UI
// siteStop(); 4W$t28)
} .uGvmD<;x
vq&u19iP
nNJMQb'K
System.err.println("文件下载结束！"); <>tQa5;
} \uTy\KA
catch(Exception e){e.printStackTrace ();} !?u{2D
} ~gAp`Q
q!+&|F
L 2k?Pl
//获得文件长度 <5wk~|@t
public long getFileSize() X|iWnz+^
{ V<%eWT)x7C
int nFileLength = -1; @CJ`T&
try{ edv&!
URL url = new URL(siteInfoBean.getSSiteURL()); G$)f5_]7{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >PBP:s1f4>
httpConnection.setRequestProperty("User-Agent","NetFox"); eVy>
$xl>YYEBMH
+>uiI4g
int responseCode=httpConnection.getResponseCode(); C%l+<wpXO
if(responseCode>=400) S[zX@3eZV
{ 9< $n'g
processErrorCode(responseCode); {+V]saYP
return -2; //-2 represent access is error eXdE?j
} i G%h-
Cj6+zJ
0~:Eo89
String sHeader; Z:2a_Atm
tDk!]
wVms"U.
for(int i=1;;i++) `$5 QTte
{ Arzyq_ Yk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ][IEzeI_LN
//Utility.log(in.readLine()); )* \N[zm
sHeader=httpConnection.getHeaderFieldKey(i); CC<(V{Png
if(sHeader!=null) ZWH9E.uj
{ Jiv%Opo/|
if(sHeader.equals("Content-Length")) #rkz:ir4
{ 2Vn~o_ga
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n8dJ6"L<"
break; >ARZ=x[
} I\DH
} XFiP8aX<
else -J<{NF
break; ev}ugRxt|k
} P wY~L3,
} E9"P~ nz
catch(IOException e){e.printStackTrace ();} vTdJe
catch(Exception e){e.printStackTrace ();} 3?+CP-T-j
6(5YvT
N#Y|MfLc
Utility.log(nFileLength); `3CdW
[7btoo|P]
OrJuE[R.
return nFileLength; Tt.#O~2:9
} oXxY$x*R1
\[57Dmo
,R~{$QUl
//保存下载信息（文件指针位置） |v6kZ0B<
private void write_nPos() 3m#/1=@o
{ aA|<W g
try{ XJ3p<
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ww[Xqmg
output.writeInt(nStartPos.length); $k,wA8OZ-
for(int i=0;i<nStartPos.length;i++) A./VO
{ Q,f~7IVX
// output.writeLong(nPos); b-+~D9U<
output.writeLong(fileSplitterFetch.nStartPos); Pd"=&Az|
output.writeLong(fileSplitterFetch.nEndPos); z3bRV{{YqN
} nN]GO}
output.close(); !d)Vr5x
} [K=M;$iQ
catch(IOException e){e.printStackTrace ();} a^ __Z3g,
catch(Exception e){e.printStackTrace ();} :Q=tGj\G
} lzE{e6
T|%pvTIe
[@&0@/s*t'
//读取保存的下载信息（文件指针位置） ZgzjRa++
private void read_nPos() I+VL~'VlS
{ /qd5{%:
try{ h|T_ k
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +'ZJ]
int nCount = input.readInt(); >OLKaghV.5
nStartPos = new long[nCount]; ,DZoE~
nEndPos = new long[nCount]; Biva{'[m
for(int i=0;i<nStartPos.length;i++) RI[=N:C^
{ A%[BCY_
nStartPos = input.readLong(); s.#%hPX{
nEndPos = input.readLong(); hp$/O4fD
} .yF@Ow
input.close(); cOq'MDr
} zarxv| }$
catch(IOException e){e.printStackTrace ();} <?&Y_
catch(Exception e){e.printStackTrace ();} >]!8f?,
} 2lc
w1&\heSQ
WCdl 25L#
private void processErrorCode(int nErrorCode) o _G,Ph!7
{ aWCZ1F
System.err.println("Error Code : " + nErrorCode); AVnH|31dC~
} C+m%_6<
_&wrA3@/L
Z"pCDW)
//停止文件下载 Q:5^K
public void siteStop() "K9/^S_
{ bih%hqny
bStop = true; dKk#j@[n"
for(int i=0;i<nStartPos.length;i++) N*w6D:
fileSplitterFetch.splitterStop(); d:X@zUR*)
X"k:+
yd|roG/
} Km)VOX[ZZ
} d$H
//负责部分文件的抓取 hb.^&
**FileSplitterFetch.java IrMUw$
*/ Lhz*o6)
package NetFox; sc0.!6^'V
zJ $&`=
'-l.2IUyT
import java.io.*; 9zL(PkC%\
import java.net.*; E xls_oSp
}mYxI^n
3T= ?!|e
public class FileSplitterFetch extends Thread { ;(3!#4`q(]
m}$7d5
E^`-:L(_
String sURL; //File URL ]wZlJK`K
long nStartPos; //File Snippet Start Position {M^BY,%*
long nEndPos; //File Snippet End Position [KMNMg
int nThreadID; //Thread's ID w:VD[\h
boolean bDownOver = false; //Downing is over TFAd
boolean bStop = false; //Stop identical # E{2 !Z
FileAccessI fileAccessI = null; //File Access interface yp!7^
A/c#2
k6$Ft.0d1Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RD|DHio%
{ }`~n$OVx
this.sURL = sURL; _yRD*2 !;
this.nStartPos = nStart; @dyh:2!
this.nEndPos = nEnd; &E+mXEve
nThreadID = id; 6KRC_-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'nT#c[x[0
} QG=K^g
II'"Nkxd
SYd6D@^2j
public void run() xjy(f~'
{ xep8CimP'
while(nStartPos < nEndPos && !bStop) fpa~~E-
{ :OFs"bC
PWBcK_4i%
KDS}"/
try{ #I"s{*
URL url = new URL(sURL); _M) G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2j;9USZ p
httpConnection.setRequestProperty("User-Agent","NetFox"); %#<MCiaK
String sProperty = "bytes="+nStartPos+"-"; 'N3)>!Y:8
httpConnection.setRequestProperty("RANGE",sProperty); b]b+PK*h
Utility.log(sProperty); ~JS BZ@
`tPVNO,l
6Qk[TL)t
InputStream input = httpConnection.getInputStream(); [Qqomm.[\w
//logResponseHead(httpConnection); 6E-AfY'<
RuGG3"|
bn%4s[CVb4
byte[] b = new byte[1024]; +P=IkbxAO
int nRead; .|e8v _2J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kW7$Gw]-
{ ]5r@`%9
nStartPos += fileAccessI.write(b,0,nRead); !T#EkMM
//if(nThreadID == 1) B#G:aBCM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mt]^d;E
} |[)n.N65=
#:NY9.\o
EeR}34
Utility.log("Thread " + nThreadID + " is over!"); =<%[P9y
bDownOver = true; ubv>*iO
//nPos = fileAccessI.write (b,0,nRead); GO)5R,
} $Jo4n>/
catch(Exception e){e.printStackTrace ();} ph$vP;}
} &/n*>%2
} 1Ror1%Q"?
i}_"
neQ~h4U"
//打印回应的头信息 [DZ|Ltv
public void logResponseHead(HttpURLConnection con) @'9m()%-]g
{ YsMM$rjP+
for(int i=1;;i++) s o1hC
{ hv`I`[/J
String header=con.getHeaderFieldKey(i); X;1yQ|su
if(header!=null) Ms#rvn!J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p,.6sk
Utility.log(header+" : "+con.getHeaderField(header)); aJQzM
else fC".K Yjp
break; @THa[|(S
} LS$zA>:
} "~mY4WVG
a4[t3U
Q5b9q$L$
public void splitterStop() e%lxRN"b
{ =4$ErwI_dm
bStop = true; %P7qA
} |\W53,n9
r )HZaq
/9=r.Vxh
} oY+p;&H
N%?R(
TuEM
/* WvZt~x&2
**FileAccess.java Z9.0#Jnu
*//文件访问(定位，写) :(\JY?+w
package NetFox; {_mVfFG
import java.io.*; G c\^Kg^#
gyb99c,)
d_Jj&:"l
public class FileAccessI implements Serializable{ Z5p [*LMO
h*R w^5,c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {a__/I>)
RandomAccessFile oSavedFile; S:XsO9:{
long nPos; Sn0kJIb }
l5 ]
T%;V_iW-
public FileAccessI() throws IOException `{|w*)mD
{ v;`>pCal
this("",0); U.5R3z
} =Oq*9=v|
T(qTipq0
;:&|DN3;
public FileAccessI(String sName,long nPos) throws IOException QWnGolN
{ vz~Oi
oSavedFile = new RandomAccessFile(sName,"rw"); @mJ~?d95v
this.nPos = nPos; 19U&4Jk
oSavedFile.seek(nPos); Ta[\BWR2
} )3)7zulnXH
L+*:VP6WD
:0,yq?M
public synchronized int write(byte[] b,int nStart,int nLen) M!kSt1
{ @H<*|3J
int n = -1; sPG500=)
try{ ;*$e8y2
oSavedFile.write(b,nStart,nLen); $_iE^zZaU^
n = nLen; v3aPHf
} DR{O.TX
catch(IOException e) 3@qv[yOE
{ op\$(7<d-
e.printStackTrace (); 3%bhW9H%
} $btu=_|f
cS'{h
zPxR=0|
return n; W7Y@]QMX
} ggL/7I(
+ c+i u6+"
b*.aaOb
} 6UqAs<c9
vJaWHC$q
h=0a9vIXF
/* i%JJ+9N
**SiteInfoBean.java Ix6\5}.c9
*/ cFt&Efj
package NetFox; XPU>} 4{
|1"&[ .
EG`6T
public class SiteInfoBean { k#zDY*kj
;Y[D#Ja-
^~.AV]t|
private String sSiteURL; //Site's URL ) $_1U!z
private String sFilePath; //Saved File's Path D;NL*4zt
private String sFileName; //Saved File's Name Uns%6o
private int nSplitter; //Count of Splited Downloading File :09NZ !!
0F@~[W|2
W} i6{Vh
public SiteInfoBean() :y~l?0b&8
{//nSplitter的缺省值为5 rgv$MnG
//default value of nSplitter is 5 KjV1->r#
this("","","",5); Y4Jaw2b
} sVS),9\}
7?Twhs.O
UN6nh T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bhjJH,%_>
{ r*Z p-}
sSiteURL= sURL; G7#<Jo<8
sFilePath = sPath; ?Ql<s8
sFileName = sName; avMre_@V
this.nSplitter = nSpiltter; t; #D,gx
?D@WXE0a
cS|W&IH1
} %&$s0=+
Cm6%wAzC
$.Qq:(O:6
public String getSSiteURL() d-UQc2r
{ Eye.#~
return sSiteURL; dr=h;[Q'
} ?&XpwJw:~
DvBRK}'
dJ,,yA*
public void setSSiteURL(String value) =W'{xG}
{ y(6*)~Dh
sSiteURL = value; h"$],=
} {@67'jL
PAjH*5IA
0e~4(2xK
public String getSFilePath() Q$S|LC
{ D14i]
return sFilePath; m@` NN
} oe1$;K>.7
\4hB1-
=@ed{~
public void setSFilePath(String value) x)2ZbIDB:"
{ MM/D5g
sFilePath = value; ,6T3:qkkvF
} ET=-r
{r[g.@
li)shp)
public String getSFileName() :}~B;s0M\
{ ^14a[ta/'
return sFileName; `< cn
} $tca: b}Mk
@O&;%IZMY
2)R*d
public void setSFileName(String value) /: }"Zb
{ 4wx_@8
sFileName = value; %1PNP<3r0
} =7%c*O <
\9jvQV/y
ood,k{
public int getNSplitter() JQ"w{O
{ L=-v>YL+
return nSplitter; KFn[
} drf?7%v
Z/[ww8b.
~g|z7o
public void setNSplitter(int nCount) \~@a/J
{ De:| T8&
nSplitter = nCount; 0X4%Ccs
} [<A|\d'x
} 2VA mL7)
Jhr3[A
;=E!xfp5U
/* o"e]9{+<
**Utility.java x`gsD3C
*/ 4^AdSuV
package NetFox; )2y# cM*
xe!6Pgcb
C.q4rr
public class Utility { .Fn7yTQ%
;UDd4@3`S"
J^<}fRw
public Utility() -}Q^A_xK
{ nEboet-#D0
3!0~/8!f@
0l>4Umxr{J
} 7!%xJ!
6,UW5389
//线程睡眠 K&>+<bJ_
public static void sleep(int nSecond) *B1%-
{ FJ(}@U}57
try{ $@Kwsoh'
Thread.sleep(nSecond); hNF.
} SK G!DKQ
catch(Exception e) "$rmy>d
{ 0L|D1_k[
e.printStackTrace (); Bi$nYV)-l
} h;?H4j
} X4Y!Z/b
xN=:*#Z"pb
//日志 KBkS>0;X
public static void log(String sMsg) .sR=Mf7T
{ 2u?k;"]V
System.err.println(sMsg); f15f)P
} EsKOzl[c:
Z_}[hz$
2UJjYrm
public static void log(int sMsg) uKE?VNC]
{ #Z>EX?VS:
System.err.println(sMsg); rf]'VJg#3
} MclW!CmJ
} mel(C1b"j/
&yN/AY`U
$F/Uk;*d!
/* }{(J*T
**TestMethod.java ZI/Ia$O
*/ ~|5B
package NetFox; 4J${gcju
o1?bqVF;6
9qXKHro
public class TestMethod { 2~(\d\k
1'Y7h;\~\
^I]A@YNni
public TestMethod() [)S&PK
{ ///xx/weblogic60b2_win.exe 0JS#{EDh+
try{ O{w'i|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IP=."w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E\lel4ai
SiteFileFetch fileFetch = new SiteFileFetch(bean); b]cnTR2E
fileFetch.start(); jNu`umS
} Lx#CFrLQ*
catch(Exception e){e.printStackTrace ();} .R5(k'g?
LOX}
KKJ)BG?qZ
} LZF%bJv
$zv&MD!&h
nTQ&nu!
public static void main(String[] args) 0AWOdd>.
{ i^2-PKPg{
new TestMethod(); \PJpy^i
} |];f?1
} vnOl-`Z ~
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