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)); =1Jo-!{{
} l))IO`s=_
for(int i=0;i<nEndPos.length-1;i++) !7?wd^C'f
{ rNp#5[e
nEndPos = nStartPos[i+1]; _gh7_P^H=d
} Z8UM0B=i
nEndPos[nEndPos.length-1] = nFileLength; gu&oCT
} ?yK\L-ad
} Y.#+Yh[
`;@4f|N9
:"]ei@
//启动子线程 _r'M^=yx[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4y.[tk5
for(int i=0;i<nStartPos.length;i++) rg.if"o
{ q5PYc.E([
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Eq{TZV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "-%H</
nStartPos,nEndPos,i); 9f`Pi:*+/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;wrgpP3
fileSplitterFetch.start(); :_ox8xS4
} 3R {y68-S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6Tnzg`0I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9_{!nQC.g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", = ;d<Ikj
nEndPos = " + nFileLength); ;0'v`ob'.?
// fileSplitterFetch[nPos.length-1].start(); cK&oC$[r-
wP*Z/}Uum+
w3D_ c~
//等待子线程结束 I"4B1g
//int count = 0; _(foJRr
//是否结束while循环 TZg7BLfy
boolean breakWhile = false; ej+!|97M
mZyTo/\0
605|*(
while(!bStop) .2xkf@OP
{ m@YLZ
write_nPos(); iY-dM(_:]
Utility.sleep(500); 9&cZIP
breakWhile = true; gZ3!2T>
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4KCxhJq
for(int i=0;i<nStartPos.length;i++) $]FWpr%)
{ ?F/3]lsggT
if(!fileSplitterFetch.bDownOver) il~,y8WTU{
{ JN_# [S$
breakWhile = false; s><co]
break; uZ+<
} P*>V6SK>b
} W=!f
if(breakWhile) /!hW6u5
break; |wDCIHzQ
q)*0G*
jJ|;Nwm<[
//count++; L6^h3*JyD
//if(count>4) J}JnJV8|G
// siteStop(); 5S1m&s5k
} H|Ems}b
x+pFu5,
e\<I:7%Rg
System.err.println("文件下载结束！"); C1=[\c~jw
} nFqMS|EN
catch(Exception e){e.printStackTrace ();} 5 F-Q&
} x?3p3[y
}49?Z3
!duR7a
//获得文件长度 `d8TA#|`
public long getFileSize() )Ii=8etdv
{ g=)@yZ3>v
int nFileLength = -1; Z]tz<YSkG
try{ b|NEU-oy
URL url = new URL(siteInfoBean.getSSiteURL()); yC[}gHv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <6@Db$-
httpConnection.setRequestProperty("User-Agent","NetFox"); >2a~hW|,
LE;c+(CAU
?g'l/xuRe
int responseCode=httpConnection.getResponseCode(); {}z7N~
if(responseCode>=400) xRfX:3
{ tm$3ZzP4
processErrorCode(responseCode); }sFHb[I &
return -2; //-2 represent access is error Jps!,Mflc
} <%5ny!]
W/ERqVZR]
r<U }lK
String sHeader; PYZ8@G
Q8_d]V=X:
!59q@Mya[
for(int i=1;;i++) W|:WAxJ*d
{ d$!ibL#o
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *`kh}
//Utility.log(in.readLine()); uB\A8zC
sHeader=httpConnection.getHeaderFieldKey(i); =_5-z|<
if(sHeader!=null) |K]tJi4fz
{ j9%=^ZoQj
if(sHeader.equals("Content-Length")) .L}ar7
{ JH 8^ZP:d'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c5JxKU_
break; MD+Q_
} #}.db?[Rv
} i9d.Ls
else Qk((H~I}
break; bS*9eX=K
} y@F{pr+dA
} cG.4%Va@s_
catch(IOException e){e.printStackTrace ();} GE|V^_|i
catch(Exception e){e.printStackTrace ();} p?5zwdX+`
,+WDa%R
_T1|_9b
Utility.log(nFileLength); )gZ yW
8q_nOGd
d+8Sypv^4*
return nFileLength; F8q|$[nH
} _k&vW(O=:
X4gs{kx}|
kIyif7
//保存下载信息（文件指针位置） |Gz(q4
private void write_nPos() f mf(5
{ }}<^fM
try{ @PutUYz
output = new DataOutputStream(new FileOutputStream(tmpFile)); L^dF )y?
output.writeInt(nStartPos.length); :U=*@p4?
for(int i=0;i<nStartPos.length;i++) ^)TZHc2a[
{ T)MKhK9\Ab
// output.writeLong(nPos); 29:] cL(5
output.writeLong(fileSplitterFetch.nStartPos); V!uW\i/
output.writeLong(fileSplitterFetch.nEndPos); #V@[<S2
} ?g}G#j
output.close(); m;'ebkq
} L\aG.\
catch(IOException e){e.printStackTrace ();} 1GE[*$vuq
catch(Exception e){e.printStackTrace ();} W|4:3c4
} rytves%;C
zt6GJz1q
]v=A}}kS
//读取保存的下载信息（文件指针位置） XU_gvz
private void read_nPos() h:xvnyaI
{ 3VaL%+T$,
try{ >4 VN1^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Qu|H_<8g
int nCount = input.readInt(); ,N93H3(
nStartPos = new long[nCount]; )\Am:?RH;
nEndPos = new long[nCount]; %g:6QS|
for(int i=0;i<nStartPos.length;i++) yw\Q>~$n[=
{ QWcQtM
nStartPos = input.readLong(); }]<0!q &xB
nEndPos = input.readLong(); S"HdjEF7\
} VYbH:4K@%
input.close(); #x*\dL
} TophV}@B`
catch(IOException e){e.printStackTrace ();} 2{|Z?3FJ^
catch(Exception e){e.printStackTrace ();} VkFMr8@|
} {^8?fJ/L
ia@ |+r
%tB7 &%ut
private void processErrorCode(int nErrorCode) Q<0X80w>
{ OYSq)!:
System.err.println("Error Code : " + nErrorCode); C cPOK2
} KT[ZOtu
,<k%'a!B
nr&bpA/
//停止文件下载 r3qKT
public void siteStop() uP G\1
{ bMn)lrsX
bStop = true; u8.F_'`z
for(int i=0;i<nStartPos.length;i++) ,BUrZA2\U$
fileSplitterFetch.splitterStop(); > a;iX.K
`*6|2
<2N{oK.
} IdqCk0lVD
} JkhWLQ>o
//负责部分文件的抓取 By waD?
**FileSplitterFetch.java k3K*{"z
*/ 'Lq+ONX5
package NetFox; 1w~PHH`~
`WIZY33V
?VlGTMaS+
import java.io.*; C~egF=w
import java.net.*; vJxEF&X
nNq<x^@83
R2v9gz;W
public class FileSplitterFetch extends Thread { FQJiLb._Z
a*-9n-U@[k
K[kK8i+(
String sURL; //File URL 9dq"x[
long nStartPos; //File Snippet Start Position 3m= _a
long nEndPos; //File Snippet End Position b"WF]x|^
int nThreadID; //Thread's ID WG A1XQ{
boolean bDownOver = false; //Downing is over f`:GjA,J$
boolean bStop = false; //Stop identical (>vyWd]
FileAccessI fileAccessI = null; //File Access interface 1aQm r=,
rCwE$5 b
o3V\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException FY^2 Y
{ :h5G|^
this.sURL = sURL; tPl 4'tW_
this.nStartPos = nStart; 0KnL{Cj
this.nEndPos = nEnd; 2HtsSS#0Q
nThreadID = id; ]L97k(:Ib
fileAccessI = new FileAccessI(sName,nStartPos);//定位 f[1cN`|z
} 4^uSW&`;/
`Jk0jj6Z
& ?xR
public void run() j1KNgAo<4
{ M#; ks9
while(nStartPos < nEndPos && !bStop) H,]8[qT<
{ &y5"0mA
#m,H1YH M
y92R}e\M
try{ Ez;Qo8
URL url = new URL(sURL); z3y{0<3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h<e
httpConnection.setRequestProperty("User-Agent","NetFox"); /kY9z~l
String sProperty = "bytes="+nStartPos+"-"; HD^#"
httpConnection.setRequestProperty("RANGE",sProperty); !{g<RS(c
Utility.log(sProperty); wkM1tKhy/
_;BwP
eJ99W=
InputStream input = httpConnection.getInputStream(); ;.V/ngaj
//logResponseHead(httpConnection); r|EN5
o5bp~.m<
J-hJqR*;K
byte[] b = new byte[1024]; S3\NB3@qC&
int nRead; zbmC?2$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C3}:DIn"w
{ #73pryXV
nStartPos += fileAccessI.write(b,0,nRead); !BsQJ_H
//if(nThreadID == 1) !l9{R8m>eJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f`n4'dG
} jc&k-d>=G
5p (zhfuG
=#2c r:1
Utility.log("Thread " + nThreadID + " is over!"); #RBrii-,
bDownOver = true; 6nZ]y&$G-k
//nPos = fileAccessI.write (b,0,nRead); ~Q&J\'GQH
} nF@**,C Q
catch(Exception e){e.printStackTrace ();} s*k)h,\
} {Rkd;`Q`!
} riDb!oC
ISGw}#}]?
<rBW6o7
//打印回应的头信息 r{;NGQYs
public void logResponseHead(HttpURLConnection con) #7]Jz.S
{ zmo2uUEd
for(int i=1;;i++) Ys.GBSlHG
{ 3^P;mQ$p1
String header=con.getHeaderFieldKey(i); 2=?3MXcjy
if(header!=null) 0=&S?J#!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %e[E@H7
Utility.log(header+" : "+con.getHeaderField(header)); .$s']' =
else j3&q?1
break; 5BA:^4zr?
} F=Xb_Gd`
} ^W sgAyCB
aEzf*a|fSV
B.=n U
public void splitterStop() Zb_A(mnzh
{ |*48J1:1y
bStop = true; }bRn&)e
} P84YriLo
ts<\n-f
8Vz!zYl
} GH':Yk
Cgln@Rz
%7-(c
/* )n"0:"Ou
**FileAccess.java =p5]r:9W
*//文件访问(定位，写) f?ycZ
package NetFox; Z^Um\f
import java.io.*; /pkN=OBR
:LB*l5\
O*/%zr
public class FileAccessI implements Serializable{ ELV~ ayp5
_QHk&-Lp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &x B^
RandomAccessFile oSavedFile; $Tv~ *|a
long nPos; !YpH\wUyvP
Y,L[0%
]#DCO8Vk
public FileAccessI() throws IOException vN v'%;L
{ Q}^Ip7T
this("",0); LmyaC2
} T~$Eh6 D
:FU?vh$)
MCTJ^g"D
public FileAccessI(String sName,long nPos) throws IOException G6{'|CV
{ FZ%h7Oe
oSavedFile = new RandomAccessFile(sName,"rw"); \15'~]d
this.nPos = nPos; 4".I*ij
oSavedFile.seek(nPos); Rs{8vV
} &c"!Y)%G
%Iflf]l
DazoY&AWE
public synchronized int write(byte[] b,int nStart,int nLen) z &P1C,n)
{ yogL8V-^4
int n = -1; %^E7Iqc
try{ \"RCJadK
oSavedFile.write(b,nStart,nLen); 2vX!j!_
n = nLen; >iFi~)i_4y
} Nd61ns(N
catch(IOException e) JAP4Vwj%j
{ y,vrMWDy
e.printStackTrace (); {,zn#hU.R
} fs%l j_t
C:<TJ
>r5s>A[YC
return n; Tn(c%ytN
} f|-%.,
*S{fyYyM
&{H LYxh
} 0N4+6k|
|;(0]
!Di*y$`}b
/* qr_:zXsob_
**SiteInfoBean.java Y SD|#0
*/ cr<ty"3\
package NetFox; n>:|K0u"
dSw%Qv*y
-mAi7[omh
public class SiteInfoBean { n6s[q-td
sj\kp ni
p}O[A`
private String sSiteURL; //Site's URL [nG@ 3n
private String sFilePath; //Saved File's Path 8S*W+l19f
private String sFileName; //Saved File's Name f<v:Tg.[
private int nSplitter; //Count of Splited Downloading File ?PST.+l
"Zq)y_1
5>*~1}0T
public SiteInfoBean() /5 6sPl 7}
{//nSplitter的缺省值为5 P gK> Z,
//default value of nSplitter is 5 Y;OqdO
this("","","",5); i*-L_!cc:
} ~k[q:$T
>,s.!vpK
1feS/l$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) dyMj=e
{ 'k(aZ"
sSiteURL= sURL; 9 9S-P}xd
sFilePath = sPath; xD3Y-d9
sFileName = sName; oD>j26Q
this.nSplitter = nSpiltter; J_ S]jE{
-^+!:0';
#Kd^t=k
} +X&b
/,m!SRJ
v?en-,{A
public String getSSiteURL() uw,p\:D&
{ xesZ7{ o
return sSiteURL; slWO\AYiO
} e;ej/)no`
mzkv/
FJl_2
public void setSSiteURL(String value) \uTy\KA
{ ++)3*+N+
sSiteURL = value; 7@*l2edXm+
} C_~hX G
gZLzE*NZ
xOAA1#
public String getSFilePath() 4$^\s5K
{ 8vL2<VT;
return sFilePath; h &R1"
} B"rfR_B2M#
S[zX@3eZV
E"l/r4*f@
public void setSFilePath(String value) 6~@S,i1
{ @ppT;9<d
sFilePath = value; yaD_c;
} 8UahoNrSt
>.)m|,
<@puWm[p
public String getSFileName() f1_b``M
{ ZWH9E.uj
return sFileName; L~PBD?l
} %Ct^{k~1
S);SfNh%CL
1"4Pan
public void setSFileName(String value) UHh7x%$n
{ } qf=5v
sFileName = value; vTdJe
} g$N/pg2>cT
e2X\ll
nbECEQ:|B
public int getNSplitter() =>kE`"{!
{ 1YrIcovi-
return nSplitter; <V~B8C!)
} 'fGB#uBt
Q2L>P<87T
+[R,wsG
public void setNSplitter(int nCount) Ww[Xqmg
{ m/T3Um
nSplitter = nCount; 5>e#SW
} nbMxQODk
} 7%Q?BH7{
+'lj\_n
Z?);^m|T
/* oE H""Bd
**Utility.java D\ ;(BB
*/ 5C|Y-G
package NetFox; qq,#bRe
UBm L:Qv
;Eer
public class Utility { ,DZoE~
OABMIgX
FoNkISzW
public Utility() Bo#,)%80
{ WCdl 25L#
J_|LGrt})
n?[JPG2X
} zFba("E Z
:]rb}1nLB
//线程睡眠 XYh)59oM%
public static void sleep(int nSecond) dKk#j@[n"
{ W0 n?S "
try{ i!a.6Gq
Thread.sleep(nSecond); ].Sz2vI
} $1E'0M`
catch(Exception e) JH|]B|3
{ lM|}K-2
e.printStackTrace (); +v.<Fw2k#
} ++=f7yu
} 28! ke
q?* z<)#
//日志 Ct<]('Hm(
public static void log(String sMsg) ]wZlJK`K
{ V"Sa9P{y"
System.err.println(sMsg); ?]AF? 0/
} +7KRoF|
=`KA@~XH4
1VR|z
public static void log(int sMsg) hjgB[ &U>
{ KbSE=3
System.err.println(sMsg); \:m1{+l
} 11((b
} Due@'
Xmm)z
! }>CEE
/* 8-PHW,1@a3
**TestMethod.java sW,JnR
*/ W8_$]}G8E
package NetFox; kRb %:*
_M) G
`oU|U!|
public class TestMethod { |[Rlg`TQ;*
eev-";c
bgYUsc*uR
public TestMethod() l86gs6>
{ ///xx/weblogic60b2_win.exe %XBMi~
try{ Miz?t*|{[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +^DDWVp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p/U{*i]t
SiteFileFetch fileFetch = new SiteFileFetch(bean); !$hi:3{U,
fileFetch.start(); x']Fe7nv
} 4Ql9VM%y
catch(Exception e){e.printStackTrace ();} X`fb\}~R(
2e9.U/9
SJ2l6
} b]gVZ-
kMx)G]
ALQ-aXJ
public static void main(String[] args) bd\%K`JQ{
{ }P'c8$
new TestMethod(); s o1hC
} 1\a.o[g3e
} Ms#rvn!J
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