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)); T5R-B=YWu
} r A`V}>Xj
for(int i=0;i<nEndPos.length-1;i++) N nRD|A
{ eX?OYDDC0j
nEndPos = nStartPos[i+1]; UvJ}b
} QiQ_bB!\
nEndPos[nEndPos.length-1] = nFileLength; };mA^xO]j
} n&L+wqJ
} y<?kzt
oQLq&zRH`f
AS!?q
//启动子线程 &b.=M>\9Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !`k1:@NZ
for(int i=0;i<nStartPos.length;i++) oL!EYbFD'Z
{ .t{MIC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9eGyyZg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]q;Emy
nStartPos,nEndPos,i); FTX=Wyr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,KF'TsFf
fileSplitterFetch.start(); bk[U/9Z\
} ed]=\Key
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +Jlay1U&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ar%%}Gx/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -Y1e8H ='
nEndPos = " + nFileLength); ^?-:'<4q$
// fileSplitterFetch[nPos.length-1].start(); @GPCwE1
Y#]+Tm(+
?L5zC+c!
//等待子线程结束 tGD6AI1"I
//int count = 0; /1Qr#OJ(]
//是否结束while循环 H7?Vybg~
boolean breakWhile = false; m.JBOq=
Hu^1[#
Nu0C;B66
while(!bStop) bh s5x
{ 10G}{
write_nPos(); 7P%%p3
Utility.sleep(500); P!$Zx)T
breakWhile = true; 2n,*Nd`
#Z}Rfk(~
w~.f
for(int i=0;i<nStartPos.length;i++) <>n0arAn
{ !xzeMVI
if(!fileSplitterFetch.bDownOver) dah[:rP,n{
{ Z_PNI#h*
breakWhile = false; b}OY4~ Y4
break; TIx|L
} @:;)~V
} a[v0%W ]u
if(breakWhile) f"B3,6m
break; R]Vt Y7}i,
(ScxLf=]
9TU88]
//count++; /Y*WBTV'
//if(count>4) "HX<,l8f%
// siteStop(); tN[L@t9#cr
} `^91%f
`0rd26Qro
Okgv!Nt8)A
System.err.println("文件下载结束！"); Y}@&h!
} y6@0O%TDN
catch(Exception e){e.printStackTrace ();} u=Fv2
} B6=ebM`q
cy*?&~;
9 ^o-EC!_
//获得文件长度 DDvh4<Hk
public long getFileSize() ~aw.(A?MI
{ BK*x] zG$
int nFileLength = -1; "B8Q:
try{ M])ZK
URL url = new URL(siteInfoBean.getSSiteURL()); w;D+y*2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?8HHA:GP
httpConnection.setRequestProperty("User-Agent","NetFox"); bf0+DvIB
|HU@ >
X#d~zk[r2
int responseCode=httpConnection.getResponseCode(); R= a|Blp
if(responseCode>=400) ai}mOyJs
{ <Q$@r?Mu]
processErrorCode(responseCode); 6Vww;1J
return -2; //-2 represent access is error ODZ5IO}v
} ]&?Y~"{cD
ckV`OaRw4
F8hw#!Aq
String sHeader; 4B=2>k
MRQ.`IoS
"b?v?V0%C
for(int i=1;;i++) Fd#?\r.
{ Ok>gh2e[c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y;nZ=9Sw
//Utility.log(in.readLine()); jATI&oX
sHeader=httpConnection.getHeaderFieldKey(i); BeCWa>54i
if(sHeader!=null) 4!$s}V=6
{ L}GC<D:
if(sHeader.equals("Content-Length")) vQ<90ZxqB
{ f5F@^QXQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l6(-I Tb
break; rJFc({ 0
} ^?$WVB
} *ohL&'y
else _C.BFE_p
break; m#ZO`W
} 17D"cP
} [qdRUV'
catch(IOException e){e.printStackTrace ();} kR]!Vr*yh
catch(Exception e){e.printStackTrace ();} b'P eH\h{
XIvn_&d;G
+${D
Utility.log(nFileLength); D*Ik7Pe
JBZUv
p7);uF^O%
return nFileLength; c;{Q,"9U
} VmCW6 G#M
:]rJGgK#
CL)lq)1(
//保存下载信息（文件指针位置） lAzjN~V
private void write_nPos() :1 (p.q=
{ 7uT:b!^f[
try{ Wqc)Fv70m
output = new DataOutputStream(new FileOutputStream(tmpFile)); a,3j,(3
output.writeInt(nStartPos.length); MepuIh
for(int i=0;i<nStartPos.length;i++) eFBeJZuE|
{ FW) x:2BG
// output.writeLong(nPos); Q9Uf.Lh2
output.writeLong(fileSplitterFetch.nStartPos); ]E_h
output.writeLong(fileSplitterFetch.nEndPos); !1n8vzs"c
} H_EB1"C;\
output.close(); jAy^J(+
} ?9! Z<H
catch(IOException e){e.printStackTrace ();} [~kdPk
catch(Exception e){e.printStackTrace ();} wUiys/OVM
} ET_W-
uA,>a>xYI
;l&4V
//读取保存的下载信息（文件指针位置） |l&vkRrN
private void read_nPos() 61/.K_%I.
{ 8%%f%y
try{ b8$gx:aJ>$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0q.Ujm=,z
int nCount = input.readInt(); \\{J'j>{f
nStartPos = new long[nCount]; _$wmI/_JM
nEndPos = new long[nCount]; <EPj$::
for(int i=0;i<nStartPos.length;i++) ^zEwA
{ CNQC^d\ h
nStartPos = input.readLong(); B.g[c97
nEndPos = input.readLong(); X/z6"*(|/
} chV9_(8
input.close(); bV edFm
} +E1I");
catch(IOException e){e.printStackTrace ();} %|^OOU}
catch(Exception e){e.printStackTrace ();} ]?Fi$3Lm
} nL$x|}XAcj
3uZJ.Fb
b !%hH
private void processErrorCode(int nErrorCode) rgSOS-ox
{ h Ggx
System.err.println("Error Code : " + nErrorCode); K=C!b?
} }8@M@
'" X_B0k
%honO@$
//停止文件下载 VOc8q-hK
public void siteStop() oq4}3bQ
{ j [rB"N`0
bStop = true; {%VV\qaC
for(int i=0;i<nStartPos.length;i++) ZAJp%
fileSplitterFetch.splitterStop(); f6_];]yP
^qg?6S4
!/^-;o7
} %V1Z~HC
} +2K:qvzZ
//负责部分文件的抓取 :Xn7Ha[f
**FileSplitterFetch.java 7]x3!AlV
*/ Nru7(ag1~
package NetFox; d~/q"r1"
3m>+-})d
.s<*'B7&
import java.io.*; %/c+`Wd/l$
import java.net.*; eVt$7d?Jw
?Zc"C
HJ2*y|u
public class FileSplitterFetch extends Thread { o]ag"Q
!eAo
L4b:F0
String sURL; //File URL kaxvPv1
long nStartPos; //File Snippet Start Position rwniOQe
long nEndPos; //File Snippet End Position &-czStQ
int nThreadID; //Thread's ID ZT[3aXS
boolean bDownOver = false; //Downing is over /erN;Oo%<
boolean bStop = false; //Stop identical Fi.aC;sx
FileAccessI fileAccessI = null; //File Access interface Qd_Y\PzS
yMZHUd
rUlS'L;$"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException kW`r=u
{ Z<#hS=eY
this.sURL = sURL; '=E3[0W
this.nStartPos = nStart; 65oWD-
this.nEndPos = nEnd; 'lo
nThreadID = id; 6oinidB[l
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |+:h|UIUQ
} GyW.2
)jCo%P/
4D$;KokZ
public void run() uK("<u|
{ Q\Gq|e*
while(nStartPos < nEndPos && !bStop) 6AvHavA^Y
{ WKpA|
Y7GF$}%UL
`k;KBW
try{ ckjrk
URL url = new URL(sURL); 2oZ9laJO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .c^ ggy%
httpConnection.setRequestProperty("User-Agent","NetFox"); :s-o0$PlJ
String sProperty = "bytes="+nStartPos+"-"; 1AHx"e,;L
httpConnection.setRequestProperty("RANGE",sProperty); 2$ !D* <
Utility.log(sProperty); Z?NEO>h7
1z*kc)=JF8
HPQ/~0$
InputStream input = httpConnection.getInputStream(); Z,c,G2D
//logResponseHead(httpConnection); D6~+Y~R
|!H?+Jj:
?X9]HlH
byte[] b = new byte[1024]; IN7<@OS7
int nRead; F_ 7H!F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 85|fyX
{ h(B,d,q"
nStartPos += fileAccessI.write(b,0,nRead); L{ho*^b
//if(nThreadID == 1) y^Vw`-e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zTo8OPr
} Aaw(Ed
I\Glc=T*
(QB+%2v
Utility.log("Thread " + nThreadID + " is over!"); aF8k/$u
bDownOver = true; 64j|}wJ$
//nPos = fileAccessI.write (b,0,nRead); .5> 20\b2
} gVU1Y6.
catch(Exception e){e.printStackTrace ();} V%CUMH =U
} ,>LRa
} Zg:gY"^
J?n<ydZSH
&hV Zx
//打印回应的头信息 C+K=[
public void logResponseHead(HttpURLConnection con) IeF keE
{ *~z#.63oZ
for(int i=1;;i++) Uh|>Skic4
{ -DO&_`kn
String header=con.getHeaderFieldKey(i); ?mRE'#
if(header!=null) Q;h3v1GC\P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {.k)2{
Utility.log(header+" : "+con.getHeaderField(header)); h<p3'
else Y:x/!-
break; GlR~%q-jiQ
} 0y%L-:/c|
} h ?#@~
W7UtA.2LT
FN )d1q(~
public void splitterStop() u/AT-er;
{ yu&Kh4AP
bStop = true; =^h~!ovj:
} X;fy\HaU
EZ#gp^$
ilEi")b=
} 3vJ12=
zTCP)x
5n:71$6[
/* h8^i\j
**FileAccess.java (;6s)z
*//文件访问(定位，写) "D> ]ES%5
package NetFox; 8?jxDW a
import java.io.*; g0#q"v55
\3{3ly~L
RR>G]#k
public class FileAccessI implements Serializable{ & 5 <**
#q4*]qGHm
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c%<2z
RandomAccessFile oSavedFile; C;#"td
long nPos; /)1v9<vM"
t*+! n.p
Uu2N9.5
public FileAccessI() throws IOException ."JzDs
{ kfpm=dKL
this("",0); 1 Nk1MGV
} H2\1gNL
&d 3HB=x
\j:gr>4
public FileAccessI(String sName,long nPos) throws IOException +G!v!(Ob+
{ /"0as_L<
oSavedFile = new RandomAccessFile(sName,"rw"); {a4xF2
this.nPos = nPos; \|{*arS
oSavedFile.seek(nPos); 9H$g?';
} ;zm ks]
^^Bm$9
u S(@?m$
public synchronized int write(byte[] b,int nStart,int nLen) $:]tcY-L9
{ BGA%"b
int n = -1; hwZ6.
try{ 8v$g
oSavedFile.write(b,nStart,nLen); s9:%s*$u
n = nLen; |?|K\UF(Y
} 9g+UJ\u^
catch(IOException e) y$v@wb5
{ L+(C5L93}
e.printStackTrace (); oEPNN'~3
} 7n [12:
k{qLkcOg=
~\-r
return n; xf[zEEt
} M@5KoMsB9
\/X{n*Hw?
8_+vb#M
} 3[iSF5%V*p
*+NZQjl'
D@}St:m}
/* B>ge, }{
**SiteInfoBean.java <?nB,U
*/ p5D5%B/
package NetFox; %h3L
'?z9,oW{
%e(9-M4*
public class SiteInfoBean { zL6 \p)y
./';P<)
GI0x>Z+
private String sSiteURL; //Site's URL d~togTs1
private String sFilePath; //Saved File's Path 0A) Vtj$
private String sFileName; //Saved File's Name f_Wkg)g
private int nSplitter; //Count of Splited Downloading File zbF:R[)
6Tm Rc
FYx `o\
public SiteInfoBean() hLDch5J5~
{//nSplitter的缺省值为5 ~ LJ>WA
//default value of nSplitter is 5 4yJ*85e]
this("","","",5); 0?J|C6XM#4
} 3/A!_Uc(
IGh !d?D
fg>B
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }[=xe(4]D
{ 0Y38T)k
sSiteURL= sURL; [9db=$v8$
sFilePath = sPath; $'J6#Vs
sFileName = sName; ;Sx'O
this.nSplitter = nSpiltter; q 2_N90u
%-1BA*J`|
~RZJ/%6F
} 0i5T] )r
0gwm gc/#
>m2<Nl}
public String getSSiteURL() 2$SofG6D}
{ ^hl]s?"3
return sSiteURL; g "K#&
} ^.Ih,@N6
@aqd'O
|%2/I>o
public void setSSiteURL(String value) _v~D{H&}
{ z'\}/k+
sSiteURL = value; Y?&DEKFbD
} T~wZ
3x(MvW30Lg
[d^:
public String getSFilePath() #^4>U&?
{ @o3R`ZgC]\
return sFilePath; 4B3irHs\Q
} zT4ulXN
TsFdy{/o*
:9!0Rm
public void setSFilePath(String value) \AtwO
{ O yH!V&w
sFilePath = value; MWn L#!
} cyHaku+
aaqd:N)
z[|PsC3i:
public String getSFileName() {xBjEhQm
{ ;Xd\$)n
return sFileName; _;J9q}X
} e>vUkP y
JV?RgFy
VM\Z<}C
public void setSFileName(String value) O"J.k&C<,
{ !OZhfMVd
sFileName = value; Dt~}9HrU
} }N#>q.M
]|$$:e^U9
U@v8H!p^i
public int getNSplitter() O[hbu![
{ b~haP.Cl:
return nSplitter; wD?=u\% &
} q5\LdI2
VG'(
?k:])^G5
public void setNSplitter(int nCount) ^/d^$
{ I_6` Z 0
nSplitter = nCount; ad$Qs3)6o
} 't]EkH]BC
} mZ5K hPvf8
18/@:u{
Y"/UYxCm|&
/* $m: a-.I
**Utility.java u<y\iZ[
*/ |phWK^
package NetFox; ~oW8GQ
{!g.255+
gJGBD9wC
public class Utility { ?n9$,-^v
+ $a:X
W];6u
public Utility() 4Ig{#}<
{ qVRO"/R
-R$FJbId
!Ub?eJp
} 8rG&CxI
[rQ(ae
//线程睡眠 $9i5<16
public static void sleep(int nSecond) gAUQQ
{ F",abp!
try{ mV(x&`Cx
Thread.sleep(nSecond); JdYF&~
} yg[;
catch(Exception e) 'TN{8~Gt*
{ .sR&9FH
e.printStackTrace (); '=b&)HbeK
} 8m[L]6F(-z
} .9fluAG
DF[b?
//日志 IK?$!jh
public static void log(String sMsg) vzm4
{ ,sJfMY
System.err.println(sMsg); x[>_I1TJ
} 75}u D
rH:X/i;D
KP7RrgOan&
public static void log(int sMsg) *4^]?Y\*
{ 8v=47G
System.err.println(sMsg); Z%9^6kdY
} iY'hkrw
} }7z+
kJeOlO[
Xsn- +e
/* '*ICGKoT
**TestMethod.java h%^kA@3F
*/ 'C>SyU
package NetFox; RH4n0=2
LXF%~^^@d
,$qs9b~
public class TestMethod { ,h`D(,?X
.F3LA6se
$q$\GOQ 9
public TestMethod() }R5&[hxh4t
{ ///xx/weblogic60b2_win.exe n rB27
try{ %R"/`N9R,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xl+a@Ggtq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &2]D+aL|h
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6ch[B`[h,
fileFetch.start(); ~JPzjE
} <~X6D?
catch(Exception e){e.printStackTrace ();} 4KSN;G
t8N9/DZ}Q
RcM0VbR"EU
} Xgc\O08
OjEA;;qq
P1>X5:
public static void main(String[] args) 7=*k@9
{ }t-|^mY>
new TestMethod(); +i!M[
} ?8}jJw2H
} uWj-tzu
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