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)); lySaJd
} NSq"\A\
for(int i=0;i<nEndPos.length-1;i++) -AE/,@\P
{ DXt^Ym5Cv
nEndPos = nStartPos[i+1]; 1<83MO;
} 2XtQ"`)
nEndPos[nEndPos.length-1] = nFileLength; eG v"&kr
} zN1;v6;
} "DpQnhvbB
JF gN
#t O!3=0
//启动子线程 Pz 'Hqvd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?<;<#JN
for(int i=0;i<nStartPos.length;i++) H #BgE29
{ =X*E(.6Ip
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fo#*_y5\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), bhmjH(.t
nStartPos,nEndPos,i); .kIf1-(<U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xh0A2bw'OP
fileSplitterFetch.start(); s__g*%@B b
} rx/6x(3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s<b7/;w'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pB./L&h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i`qh|w/b_
nEndPos = " + nFileLength); =S,<yQJ
// fileSplitterFetch[nPos.length-1].start(); 9o`3g@6z
7 SZR#L
.Dm{mV@*T
//等待子线程结束 5*$Zfuf
//int count = 0; KfNXX>'
//是否结束while循环 :X f3wP=
boolean breakWhile = false; *$VurqLn
JyO lVs<T
%a `dOEO
while(!bStop) k:Q<Uanc[
{ %Qq)=J<H;
write_nPos(); 6K}=K?3Z
Utility.sleep(500); iE(grI3
breakWhile = true; t^hkGYj!2
@{uc
#EUgb7
for(int i=0;i<nStartPos.length;i++) {9 O`/|
{ +bW|Q>u
if(!fileSplitterFetch.bDownOver) @_3$(*n$~
{ x(=x;X$[^
breakWhile = false; cmI#R1\
break; ub5hX{uT
} Hea<!zPH
} ;kBies>V
if(breakWhile) `@7tWX0
break; 03@|dN
\<**SSN
<J-Z;r(gQN
//count++; -::%9D}P|
//if(count>4) CN(4;-so)
// siteStop(); 46Nf|~
} HU9y{H
(_ah~VnO
.Er/t"Qs;
System.err.println("文件下载结束！"); '.,.F0{x
} 8 -A7
catch(Exception e){e.printStackTrace ();} VsEAo
} JxJntsn
+_P 2S
PBtU4)
//获得文件长度 \DK*> k
public long getFileSize() &,]+>
{ @~3c"q;i7
int nFileLength = -1; (}1f]$V
try{ {LHe 6#
URL url = new URL(siteInfoBean.getSSiteURL()); _`>7 Q),7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rJp6d:M
httpConnection.setRequestProperty("User-Agent","NetFox"); ]bb}[#AY
/g'-*:a
<z2mNq
int responseCode=httpConnection.getResponseCode(); ^1=|(Z/
if(responseCode>=400) +Q31K7Gr
{ y$o=\:
processErrorCode(responseCode); +z0}{,HX
return -2; //-2 represent access is error : "te-
} "B3:m-'
f*{;\n(.t
Ba|}C(Ws?
String sHeader; i0Q _f!j
Eu.qA9,@U
U^BXCu1km
for(int i=1;;i++) 2_n*u^X:_
{ 3Lki7QW`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LoE(W|nj
//Utility.log(in.readLine()); <Cu?$
sHeader=httpConnection.getHeaderFieldKey(i); e-3pg?M
if(sHeader!=null) O&iYGREO
{ tkqBCKpDa
if(sHeader.equals("Content-Length")) ZM`P~N1?)g
{ a9zph2o-
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x9A ZS#e)[
break; zN/~a)
} `)M\(_
} % 3-\3qx*
else IC.<)I
break; &iy(oM
} g{)H" 8L
} nvo1+W(%
catch(IOException e){e.printStackTrace ();} Ja=70ZI^6
catch(Exception e){e.printStackTrace ();} xWz;5=7a]
_ZM9 "<M-X
"4uUI_E9F;
Utility.log(nFileLength); kjC{Zr
XW_xNkpL5c
8t:&#h
return nFileLength; 0$Y 9>)O
} w<>6>w@GZ
?En| _E_C
<`j[;>O
//保存下载信息（文件指针位置） 2vdQ&H4
private void write_nPos() *a,.E6C*
{ ) v5n "W
try{ 7h9[-d6
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4O_+4yS
output.writeInt(nStartPos.length); 3r:)\E+Q_
for(int i=0;i<nStartPos.length;i++) *r,&@UB
{ U"y'Kd
// output.writeLong(nPos); _q$LrAT
output.writeLong(fileSplitterFetch.nStartPos); ca3BJWY}J
output.writeLong(fileSplitterFetch.nEndPos); yb{{ z@
} GHC?Tp
output.close(); k-cIb@+"
} f@Rpb}zg+C
catch(IOException e){e.printStackTrace ();} KR+BuL+L
catch(Exception e){e.printStackTrace ();} 4B8Se
} Y:!/4GF
]VG84bFm
K1/gJ9+(\
//读取保存的下载信息（文件指针位置） {&}/p-S
private void read_nPos() 4IP\iw#w
{ e(=~K@m
try{ /z)3gsF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @S"pJeP/f
int nCount = input.readInt(); a3dzok
nStartPos = new long[nCount]; Hl2f`GZ
nEndPos = new long[nCount]; CpRu*w{
for(int i=0;i<nStartPos.length;i++) R!k<l<9q
{ R-A'v&=
nStartPos = input.readLong(); 2u*h*/
nEndPos = input.readLong(); B?lBO V4v4
} g3~~"`2
input.close(); lc3S|4
} 3pTS@
catch(IOException e){e.printStackTrace ();} kV:FJx0xP
catch(Exception e){e.printStackTrace ();} ;Ma/b=Y
} F'>GN}n
a j@C0
T5dUJR2k$
private void processErrorCode(int nErrorCode) $dZ>bXUw:
{ &. =}g]
System.err.println("Error Code : " + nErrorCode); ELrZ8&5G
} "gbnLKs
q?Ku}eID3
UC+7-y,
//停止文件下载 `mKlv~$1^
public void siteStop() > 0Twr
{ BsK|:MM]
bStop = true; aFr!PQp4{
for(int i=0;i<nStartPos.length;i++) k99gjL`
fileSplitterFetch.splitterStop(); b1+hr(kMRM
9oje`Ay
#7~tL23}]
} I*:qGr+ WJ
} J|"nwY}a9
//负责部分文件的抓取 x?f0Hk+
**FileSplitterFetch.java N(_ .N6
*/ z>mZT.
package NetFox; /nY).lSH
e>,9]{N+$
9QOr,~~s
import java.io.*; h8#5vO2
import java.net.*; dE5 5
~~xyFT+{F
4C,kA+P
public class FileSplitterFetch extends Thread { X"TUe>cM
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z{`6#
String sURL; //File URL <;z[+6T
long nStartPos; //File Snippet Start Position $#G6m`V
long nEndPos; //File Snippet End Position 'Vm5Cs$
int nThreadID; //Thread's ID z)&naw.
boolean bDownOver = false; //Downing is over 4/HY[FT
boolean bStop = false; //Stop identical D%;wVnUw
FileAccessI fileAccessI = null; //File Access interface !c4)pMd
sP6 ):h
ZTh?^}/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1Nl&4YLO
{ Q/QQ:t<XUi
this.sURL = sURL; qab) 1ft
this.nStartPos = nStart; VBbUl|X\
this.nEndPos = nEnd; %="~\1y
nThreadID = id; 5Cc6, ]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dm|gSv8d,
} BN\fv,
` $.X[\*U
`z3|M#r\;
public void run() $ DDSN
{ } g3HoFC
while(nStartPos < nEndPos && !bStop) /FP~jV!z
{ d7W%zg\T
FX|0R#4vm
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try{ Jw:Fj{D
URL url = new URL(sURL); ub`z7gL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .8T\Nr\~2
httpConnection.setRequestProperty("User-Agent","NetFox"); IwTr'}XIw
String sProperty = "bytes="+nStartPos+"-"; gro7*<
httpConnection.setRequestProperty("RANGE",sProperty); rPiiC/T.`
Utility.log(sProperty); YW8K $W
W>p\O9BG
5E]UI YAkV
InputStream input = httpConnection.getInputStream(); hi;WFyJTu
//logResponseHead(httpConnection); wUZQB1$F
NK+FQ^m[
'^Pq(b~
byte[] b = new byte[1024]; (j8GiJ]{L,
int nRead; u;+%Qh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?G4iOiyt
{ c&Gz> L
nStartPos += fileAccessI.write(b,0,nRead); kF(Ce{;z
//if(nThreadID == 1) K,x$c %
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tr}KPdE
} K[Yc<Q
z3^RUoGU
7XUhJN3n
Utility.log("Thread " + nThreadID + " is over!"); eZ!yPdgy|
bDownOver = true; f![xn2T
//nPos = fileAccessI.write (b,0,nRead); y!7B,
} ?-pxte8
catch(Exception e){e.printStackTrace ();} P<>[e9|
} I6K7!+;2
} ,pDp>-vI%
3 R5%N ~
?gd'M_-J,
//打印回应的头信息 z6p#fsD
public void logResponseHead(HttpURLConnection con) -]Q3/"Q
{ %$/=4f.j
for(int i=1;;i++) D-Bv(/Pz]$
{ 51&|t#8h
String header=con.getHeaderFieldKey(i); vn|TiZ
if(header!=null) }7iUagN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3xBN10R#
Utility.log(header+" : "+con.getHeaderField(header)); 5c<b|
else MS{Hz,I,
break; m3U+ du
} ^D9 /
} eZynF<i
:6 Uk)
!(B_EM
public void splitterStop() !aQIh
{ d>^~9X
bStop = true; 5>'?:jY
} fkW3~b
nURvy}<r
2#'rk'X,K
} |d~B]65t
d>YmKTk"
G{F6
/* !c\7
**FileAccess.java X"kXNKV/n
*//文件访问(定位，写) >ysriPnQ
package NetFox; .KFA218h*x
import java.io.*; l!\1,J:}Z
`!zQ
n)tU9@4Np
public class FileAccessI implements Serializable{ B:e.gtM5
i B%XBR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dj3|f{kg{
RandomAccessFile oSavedFile; &K06}[J
long nPos; +*n]tlk
USE [N
ah 4kA LO
public FileAccessI() throws IOException P\.WXe#j
{ .H Fc9^.*
this("",0); cL?\^K)
} D._{E*vg
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Dz,uS nnm
public FileAccessI(String sName,long nPos) throws IOException \^yXc*C
{ D=2~37CzQ1
oSavedFile = new RandomAccessFile(sName,"rw"); =nLO?qoe
this.nPos = nPos; \.5F](:
oSavedFile.seek(nPos); k - FB
} Z#CxQ D%\
\$'R+k-57;
M#`{>R|
public synchronized int write(byte[] b,int nStart,int nLen) <sa #|Y$
{ yU*u
int n = -1; %=y;L:S\p
try{ YFG-U-t3
oSavedFile.write(b,nStart,nLen); T]^?l
n = nLen; N"S3N)wgd
} ,cLH*@
catch(IOException e) g&Z"_7L~
{ N A8 sN
e.printStackTrace (); _jW>dU^B
} 9p5= _
yGRR8F5>(
M/*Bh,M`
return n; *K`x;r
} (m6EQoW^s+
^#2xQ5h
Umij!=GPG^
} nZ~kZ |VS
</,.K`''W
cxgE\4_u"
/* 1^S'sWwe
**SiteInfoBean.java l@xWQj9
*/ =`JW1dM
package NetFox; cbfDB^_
U4=]#=R~o
]7*kWc2
public class SiteInfoBean { ;3mL^
Is ot4HLM
iZC>)&ax
private String sSiteURL; //Site's URL KVg[#~3
private String sFilePath; //Saved File's Path ?gU}[]
private String sFileName; //Saved File's Name Z A[)
private int nSplitter; //Count of Splited Downloading File 00"CC
/\d(c/,4
rjXnDh]MC
public SiteInfoBean() *u}'}jC1X
{//nSplitter的缺省值为5 3\1#eK'TK.
//default value of nSplitter is 5 h 5Hr[E1
this("","","",5); Sg_O?.r
} 9YAM#LBTWi
*-6?
iM"asEU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v_.HGGS
{ 0JK2%%
sSiteURL= sURL; +N7"EROc
sFilePath = sPath; w~]T<^fW~
sFileName = sName; \Y+")
this.nSplitter = nSpiltter; w=|py>%
RJ@\W=aZ
JwB"\&'1ZS
} cu)U7
@cPflb
Vu%n&uF
public String getSSiteURL() YKY2Cw
{ yWNOG 2qAP
return sSiteURL; &f"T,4Oh
} 7|Xe&o<n
L1:nfH&:'
b;*c:{W)
public void setSSiteURL(String value) EZ/^nG
{ W+K.r?G<j
sSiteURL = value; Xo\S9,s{
} Ia#"/`||
<*_o0;h|
d+0^u(gc!8
public String getSFilePath() nZxSMN0]
{ &8n?
return sFilePath; ?~Pv3'%d
} Y([d;_#P
-R:X<eb
[ZD[a6(94
public void setSFilePath(String value) hXc}r6<B
{ AX;c}0g
sFilePath = value; '$?du~L-
} 'AWp6L@
F5U|9<
sBU_Ft
public String getSFileName() N}DL(-SQ3
{ ' Rc#^U*n
return sFileName; Z%OW5]q
} b)`pZiQP
>Mw'eQ0(y
}vY.EEy!
public void setSFileName(String value) t!:)L+$3
{ o0l74
sFileName = value; AuXs B
} W~yLl%
`BjR.xMv
Zw#<E =\
public int getNSplitter() |mOMRP#'
{ :v)6gz(p
return nSplitter; r**f,PDZ
} Bzw19S6y
{[P!$ /
b]i>Bv
public void setNSplitter(int nCount) vY_eDJ~'
{ tF%QH[
nSplitter = nCount; -?z\5z
} ,rai%T/rL
} I0_Ecp
N571s
x[x(y{&~
/* u{Ak:0G7
**Utility.java l `R KqT+
*/ /NU103F yt
package NetFox; 5gshKmt_
V&iS~V0.
wDKELQ(yH
public class Utility { {OP~8e"
'yr{^Pek
~b6GrY"vB
public Utility() NO4Z"3Pd_
{ S/7l/DFb
pV=@sz,G
0>FE%
} RX>2~^
&a6,ln:P
//线程睡眠 ?Oc -aa
public static void sleep(int nSecond) kP^*hO!%
{ X!c?CL
try{ w.^yP7:
Thread.sleep(nSecond); +?AW>&68y
} ``4?a7!!
catch(Exception e) p9iu:MucD<
{ V;;#/$oU:4
e.printStackTrace (); N}mh}
} ~},W8\C>
} Z0\Iyc G
t^U^Tr
//日志 AY88h$a
public static void log(String sMsg) R6P\T\~E
{ QC7k~I8
System.err.println(sMsg); CA*~2|
} $>r5>6
:)4*^a/lC
U&W"Ea=R/
public static void log(int sMsg) `0@z"D5c
{ YlKFw|=
System.err.println(sMsg); Y.-S=Y
} no&-YktP}
} YtYy zX5u7
P=gJAE5
b-%l-u
/* f^e&hyC
**TestMethod.java 8,*3zVk-
*/ Q0>q:aj\
package NetFox; 'RLOV
CXAVGO'xw
1EsqQz*$u
public class TestMethod { onnugj3
-_>.f(1
r?3Aqi"
public TestMethod() Yqj+hC6>,
{ ///xx/weblogic60b2_win.exe B9#;-QO
try{ ~kb{K;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); PeNF+5s/K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); vpLMhf`
SiteFileFetch fileFetch = new SiteFileFetch(bean); R=$Ls6z
fileFetch.start(); Qxq-Mpx{
} h<NRE0-
catch(Exception e){e.printStackTrace ();} 8Z8Y[p
e=>%^F
G~!C=l
} (B}+h
>| m.?{^
9rcI+q=E
public static void main(String[] args) Y[G9Vok VX
{ 6fGK(r
new TestMethod(); .NnGVxc5*
} 1;&T^Gdj
} tX?J@+
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