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)); mY3x (#I
} C;;dCsiV5
for(int i=0;i<nEndPos.length-1;i++) avk0pY(n
{ $3%EKi
nEndPos = nStartPos[i+1]; 69,;=
} t1.5hsp
nEndPos[nEndPos.length-1] = nFileLength; A=|&N%lP'
} e ?H`p"l
} V4Ql6vg_f
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Vo"\nj
//启动子线程 #f~#38_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :NO'[iE
for(int i=0;i<nStartPos.length;i++) ;e_n7>'#%
{ h5ST`jZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BxO8oKe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hHdH#-O:4"
nStartPos,nEndPos,i); 'zZN]P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #tdI;x3
fileSplitterFetch.start(); Jpws1~
} H{`S/>)[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <`a!%_LC [
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); grnlJ=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z@ *^4Ve
nEndPos = " + nFileLength); a%sr*`
// fileSplitterFetch[nPos.length-1].start(); W)?B{\
aDTNr/I
/WB^h6qg
//等待子线程结束 \:\rkc9LI
//int count = 0; O[;>Y'zqC%
//是否结束while循环 < ppg$;
boolean breakWhile = false; u:3~Ius
=zt@*o{F
kl_JJX6jPP
while(!bStop) Edc< 8-
{ ;+`t[ go
write_nPos(); Y dmYE$
Utility.sleep(500); ub6=^`>h
breakWhile = true; @]t}bF]
4WZ:zr N
4}Y2 B$
for(int i=0;i<nStartPos.length;i++) -S OP8G
{ xf?*fm?m
if(!fileSplitterFetch.bDownOver) sME3s-
{ nWfOiw-t
breakWhile = false; I8)x0)Lx
break; (qnzz!s
} 3@*J=LGhKc
} lphQZ{8
if(breakWhile) r:2G11[
break; +HQX]t:Y
(2Z-NVU#
9H$#c_zrq
//count++; ds,NNN<HW
//if(count>4) (\>3FwFHW|
// siteStop(); +;tXk
} hMh8)S
iF?4G^
%Iw6oG
System.err.println("文件下载结束！"); _$]3&P
} (PE x<r1
catch(Exception e){e.printStackTrace ();} 9o"k 7$
} V<Q''%k
+1~Y2
0qqk:h
//获得文件长度 k*d0ws#<l
public long getFileSize() Q\z6/1:9Z
{ /qa{*"2Qo
int nFileLength = -1; Tz[ck'k
try{ \3LP@;Phn
URL url = new URL(siteInfoBean.getSSiteURL()); {b6| wQ\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z^j7wMQ
httpConnection.setRequestProperty("User-Agent","NetFox"); kHygif !I4
)-%3;e<w
I !=ew |
int responseCode=httpConnection.getResponseCode(); kAA1+rG
if(responseCode>=400) =VFi}C/
{ 'hN_H}U
processErrorCode(responseCode); :rd{y`59>&
return -2; //-2 represent access is error T^> ST
} Zvz Zs
kVR_?ch{
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String sHeader; hkB/ OJ
v1h\ 6r'
)voJq\Y)%
for(int i=1;;i++) Is1P,`*!
{ <ZO"0oz%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /.P9n9
//Utility.log(in.readLine()); `Y>'*4a\
sHeader=httpConnection.getHeaderFieldKey(i); Z0HfrK#oU
if(sHeader!=null) blO(Th&
{ @yp#k>
if(sHeader.equals("Content-Length")) 3m%oXT
{ n@|5PI"bx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0z&]imU
break; 3,`I\>No
} O*0%AjT6
} 6G.(o
else 'EzKu~*
break; s^f7w
} }C-K0ba7
} E2dl}S zp
catch(IOException e){e.printStackTrace ();} NULew]:5
catch(Exception e){e.printStackTrace ();} jN))|eD0x
[g)HoR=&
%8Eu{3
Utility.log(nFileLength); #gW"k;7P
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return nFileLength; 6Qtyv
} O2xbHn4
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Sc b'
//保存下载信息（文件指针位置） u@&e{w~0
private void write_nPos() ;wGoEN
{ 0'wchy>
try{ mIW8K ):
output = new DataOutputStream(new FileOutputStream(tmpFile)); |"]#jx*8KC
output.writeInt(nStartPos.length); F8xz^UQO
for(int i=0;i<nStartPos.length;i++) Hk&op P9)
{ n_~u!Ky_P
// output.writeLong(nPos); -gn!8G1
output.writeLong(fileSplitterFetch.nStartPos); 74_':,u;]~
output.writeLong(fileSplitterFetch.nEndPos); qa-%j+
} jk(tw-B
output.close(); |P_voht
} >]{{5oOQ>
catch(IOException e){e.printStackTrace ();} \/XU v(
catch(Exception e){e.printStackTrace ();} ":v^Y 9
} B*Z}=$1j
^8.s"4{
pyUzHF0
//读取保存的下载信息（文件指针位置） &/m0N\n?
private void read_nPos() ^%5;Sc1V
{ pTB1I3=.u
try{ m@Hg:DY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g)!d03Qoy
int nCount = input.readInt(); c1tM(]&
nStartPos = new long[nCount]; i[Qq,MmC
nEndPos = new long[nCount]; [_T6
for(int i=0;i<nStartPos.length;i++) &s#OiF8
{ dzk1!yy
nStartPos = input.readLong(); h ?_@nQ!
nEndPos = input.readLong(); QXI#gA =
} ,_K y'B
input.close(); w`GjQIA
} :(Ak:
catch(IOException e){e.printStackTrace ();} LbkQuq/d
catch(Exception e){e.printStackTrace ();} n +v(t
} h3e %(a
`\beQ(g
F4NMq&_
private void processErrorCode(int nErrorCode) fJ GwT
{ /&N\#;kK?b
System.err.println("Error Code : " + nErrorCode); Ddh
} I*z|_}$
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f4O}WU}l{s
//停止文件下载 5{gv\S1
public void siteStop() 7aS%;EU
{ <<DPer2
bStop = true; BN&eU'Dl]
for(int i=0;i<nStartPos.length;i++) `*o ko[\3
fileSplitterFetch.splitterStop(); =qvn?I^/
FwE<_hq//
U:AB%gr[
} 5d;(D i5z
} WN $KS"b6}
//负责部分文件的抓取 Z*R~dHr
**FileSplitterFetch.java /2Z7
*/ W K(GR\@
package NetFox; !q~f;&rg
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:IO"' b
import java.io.*; ~tLvD[n[
import java.net.*; "r=p/"4D
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]k$:sX
public class FileSplitterFetch extends Thread { ,V9r2QY
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dy~M5,zn
String sURL; //File URL !gL1
long nStartPos; //File Snippet Start Position CHi t{ @9
long nEndPos; //File Snippet End Position 4Wu(Tps
int nThreadID; //Thread's ID usNq]
boolean bDownOver = false; //Downing is over 8M0<:p/
boolean bStop = false; //Stop identical _}gfec4o
FileAccessI fileAccessI = null; //File Access interface .NJ Ne
]5Q)mWF
4av
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (Z0.H3
{ "!Nu A
this.sURL = sURL; J vl-=~
this.nStartPos = nStart; {z9,CwJan?
this.nEndPos = nEnd; ?Ld:HE
nThreadID = id; P_P~c~o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =Qn8Y`U
} sY[!=`@
rM4Ri}bS
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public void run() i)/#u+Y1P
{ ;Za^).=
while(nStartPos < nEndPos && !bStop) L*P*^I^1
{ <'jygZ(
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_ t.E_K
try{ wH\ K'/
URL url = new URL(sURL); ?es9j]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ('`mPD,
httpConnection.setRequestProperty("User-Agent","NetFox"); -^*8D(j*
String sProperty = "bytes="+nStartPos+"-"; p`S~UBcL.
httpConnection.setRequestProperty("RANGE",sProperty); Gx|/ Jq
Utility.log(sProperty); 29W`L2L
-j^G4J
@7sHFwtar?
InputStream input = httpConnection.getInputStream(); ,!^g8zO
//logResponseHead(httpConnection); 6J965eM'[
8SBa w'a
PKev)M;C+
byte[] b = new byte[1024]; SbobXTbG
int nRead; CX7eCo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5r0Sl89J
{ rm<`H(cT
nStartPos += fileAccessI.write(b,0,nRead); ?QcS$i
//if(nThreadID == 1) S,s") )A1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .4!wp&
} orEb+
wh3Wuh?x
^J@ Xsl
Utility.log("Thread " + nThreadID + " is over!"); ']sIU;h3
bDownOver = true; -}5dZ;
//nPos = fileAccessI.write (b,0,nRead); 08$l=
} rY"EW"y
catch(Exception e){e.printStackTrace ();} /b{Ufo3v
} I^O`#SA(
} j[w5#]&%
Iy2AJ|d.
S3dcE"hg
//打印回应的头信息 OQ<NB7'n0A
public void logResponseHead(HttpURLConnection con) LfsOGC
{ CasFj9,
for(int i=1;;i++) 8yGo\\=T
{ "; ?^gA
String header=con.getHeaderFieldKey(i); Bn Nu/02.=
if(header!=null) mTa^At"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Csm23QLsg)
Utility.log(header+" : "+con.getHeaderField(header)); wHErF #xo
else ZQ~EaI9R
break; k= 9a/M u
} l 4cTN @E
} (XQl2C
-vS7%Fbr
.:;#[Z{-
public void splitterStop() 3 J\&t4q
{ h='@Q_1Sb
bStop = true; KkZo|\V
} %[m%QP1;p
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":^cb =
} ;7yt,b5&C
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3q1u9`4;
/* ptpu u=3"
**FileAccess.java oz?6$oE(bt
*//文件访问(定位，写) {qBbzBG
package NetFox; btB> -pT
import java.io.*; S]DYEL$
_+nlm5
v:Z.8m8D
public class FileAccessI implements Serializable{ ]m""ga
0bG2YMs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f@J-6uQ7w
RandomAccessFile oSavedFile; J_ `\}55n
long nPos; O0>^?dsL
%D*yXNsY
%-[U;pJe;
public FileAccessI() throws IOException w77"?kJ9X
{ C AF{7 `{
this("",0); 3.I:`>;EO
} zI3Bb?4.
qn@:A2ed
.cm$*>LW:x
public FileAccessI(String sName,long nPos) throws IOException Uzd\#edxJ
{ =Qw`F0t
oSavedFile = new RandomAccessFile(sName,"rw"); 6\?<:Qto
this.nPos = nPos; ,(CIcDJ2U_
oSavedFile.seek(nPos); fmq9u(!R
} _cH 7lO[
8Dy;'BtT
~@bh[o~rF
public synchronized int write(byte[] b,int nStart,int nLen) <f`G@
{ 421ol
int n = -1; |0/~7l
try{ khtSZ"8X
oSavedFile.write(b,nStart,nLen); fP:g}Z
n = nLen; 6'qC *r
} [!#<nY/C
catch(IOException e) :*/`"M)'
{ V3$Yr"rZ;
e.printStackTrace (); Q{+&3KXH
} -:o4|&g<*
<;Bv6.Z
X,8]g.<
return n; %2D9]L2Up
} mdTCe HX
/a!M6:,pX
~1v5H]T{
} 6S#e?>"+
\P|PAU@,
&I$MV5)u
/* %Cz&7qf"
**SiteInfoBean.java 7U\GX
*/ $kef_*BQg
package NetFox; N8^AH8l
{"uLV{d
:v!e8kM\x
public class SiteInfoBean { .v{ok,&
{FU,om9
u 6(O;
private String sSiteURL; //Site's URL +bw>9VmG
private String sFilePath; //Saved File's Path Bqd'2HQd
private String sFileName; //Saved File's Name af<R.
private int nSplitter; //Count of Splited Downloading File MIJ^n(-G
'-7rHx
cn$o$:tW
public SiteInfoBean() =k\V~8XZ
{//nSplitter的缺省值为5 sV))Z2sq
//default value of nSplitter is 5 kgV_*0^
this("","","",5); $R2iSu{kO
} B~RVFc +
7xIXFuu
ROyG+dUy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +I {ZW}rA
{ %9!,PeRe
sSiteURL= sURL; vO#=]J8`
sFilePath = sPath; qQu}4Ye>
sFileName = sName; .MzVc42<
this.nSplitter = nSpiltter; '*~_!lE5
+ S^OzCGk
AUm"^-@x#>
} 4iD-jM_D
q`l%NE
8tR(i[L
public String getSSiteURL() 1yS[;
{ o&GS;{Rs
return sSiteURL; ur,!-t(~t
} vjcG F'-
O"$uw
LK}Ih@f
public void setSSiteURL(String value) IezOal
{ PtUea
sSiteURL = value; WPmH4L>T
} 0Y_?r$M
wE.CZ%f
Vy:I[@6@+
public String getSFilePath() ' DZYN {}
{ \{HbL,s
return sFilePath; (}W+W\.
} E,S[3+
OO Hw-MW
x +=zG4Hm
public void setSFilePath(String value) "%o,P/<X
{ H\Y5Fd9)
sFilePath = value; 7hs1S|
} lTe7n'y^^
8!~8:?6n
OT*C7=
public String getSFileName() Ho}"8YEXNV
{ ''{REFjK7
return sFileName; -VqZw&"
} kK27hfsw
$)1i)/]9U
yJCqP=
public void setSFileName(String value) 66P'87G
{ WF)(Q~op0U
sFileName = value; 0Jz5i4B
} n9 LTrhLqp
3@qy}Nm
0zQ^ 6@
public int getNSplitter() @H{QHi
{ O_zW/#
return nSplitter; 9{D u)k
} i++a^f
+VJS/
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public void setNSplitter(int nCount) n(i Uc1Y
{ ;_o1{?~
nSplitter = nCount; y$ L@!r/s
} g[oa'.*OB
} +3a}~pW
9j0Hvo%T
m*Zq3j
/* $+ z3
**Utility.java W'|NYw_B
*/ J`E,Xw>2
package NetFox; 1JRM@!x
#%4XZ3j#j;
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public class Utility { jGg,)~)Y
y:Wq;xEiDo
7Ei,L[{\i#
public Utility() wbIgZ]o!/;
{ @q98ac*{
s+tPHftp
I_1(jaY
} (yx^zW7
_Sq*m=
//线程睡眠 9HsiAi*
public static void sleep(int nSecond) X#ZQpo'h
{ .wU0F
try{ j*.K|77WHj
Thread.sleep(nSecond); YiO3.+H
} 6'{/Ote
catch(Exception e) _>8rTk`/h
{ ,Y:ET1:
e.printStackTrace (); `D%U5Jb
} Wc*jTip
} &RJ*DAmL
^n?`l ^9c$
//日志 /5!0wxN
public static void log(String sMsg) V< Ib#rd'
{ 5*O*p `Ba
System.err.println(sMsg); J~]Y
} ~WjK'N4n5
HUA{ P%
"t.Jv%0=
public static void log(int sMsg) 0P5s'2w
{ ]c9\[Kdq}H
System.err.println(sMsg); yTxrbE
} C`@gsF"<7
} CN{xh=2qY[
(#c|San
tD~ nPbbB
/* e=cb%
**TestMethod.java u|mTF>L
*/ r4isn^g
package NetFox; }@y(-7t
/E39Z*
:`>$B?x+
public class TestMethod { 4St-Q]Y _
lR>p
+a'LdEp
public TestMethod() /szwVA
{ ///xx/weblogic60b2_win.exe ELN1F0TneH
try{ ;e"dxAUe!^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Op'&c0l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); '8yCwk
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'ti~TG
fileFetch.start(); bess b>=
} Hl#?#A5
catch(Exception e){e.printStackTrace ();} +8|9&v`
E!9(6G4
EzeU-!|W
} n *EGOS
^OOoo2
lu?:1V-
public static void main(String[] args) ]$,3vYBf
{ #`ZBA>FLaQ
new TestMethod(); b8 E{~z
} a&Z,~Vp
} G=F_{z\}
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