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)); ng&EGM
} ?#EXG
for(int i=0;i<nEndPos.length-1;i++) J"2ODB5"
{ FG5c:Ep
nEndPos = nStartPos[i+1]; HT,kx
} WO(&<(?
nEndPos[nEndPos.length-1] = nFileLength; C"Y]W-Mgg
} 3Llj_lf
} Zqs-I8y
L]}RSE2
2bn@:71`
//启动子线程 P7k$^n
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k@";i4}A
for(int i=0;i<nStartPos.length;i++) Rn~Xu)@e
{ ME10dr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _hyxKrm' 6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aEqI51I
nStartPos,nEndPos,i); n40MP5RxY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lKhh=Pc2
fileSplitterFetch.start(); SX=0f^
} <sCq x/L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !E:Vn *k;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %Rsf6rJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =Wy`X0h
nEndPos = " + nFileLength); wAOVH].
// fileSplitterFetch[nPos.length-1].start(); nM.?Q}yO~
Nj-rZ%&
:k )<1ua
//等待子线程结束 eZod}~J8
//int count = 0; ocuVDC
//是否结束while循环 UrcN?
boolean breakWhile = false; PUZXmnB
aCi^^}!
pOI`,i}.
while(!bStop) >eTgP._
{ $E,DxDT
write_nPos(); 2SPFjpG8n
Utility.sleep(500); =O'%)Y&
breakWhile = true; fYQi#0drn
i`nw"8
ryp$|?ckJ
for(int i=0;i<nStartPos.length;i++) Ce'2lo
{ .nF
if(!fileSplitterFetch.bDownOver) kq.h\[
{ AW&s-b%P
breakWhile = false; l 75{JxZX
break; O-lh\9{'R
} 07"Oj9NlA
} W]}V<S$
if(breakWhile) ;ld~21#m
break; a={qA4N
I;Fy k70w;
"gikX/Co=
//count++; I nK)O';
//if(count>4) V\`="
// siteStop(); wYMX1=
} *n_4Rr
8Gg/M%wq9U
ZUJOBjb` K
System.err.println("文件下载结束！"); c2mt<DtWW
} g7LW?Ewr
catch(Exception e){e.printStackTrace ();} ,Ve@=<
} Cl.T'A$
N5Mz=UgB
j4SGA#;v
//获得文件长度 Bt7v[Ot
public long getFileSize() 10 H!
{ k Q(y^tW
int nFileLength = -1; )$4DH:WN
try{ EEZ2Gu6c
URL url = new URL(siteInfoBean.getSSiteURL()); 71&+dC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gG;W:vR}l
httpConnection.setRequestProperty("User-Agent","NetFox"); to|9)\
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int responseCode=httpConnection.getResponseCode(); w]-iM
if(responseCode>=400) htrj3$q(4
{ 9x{prCr
processErrorCode(responseCode); +vSE}
return -2; //-2 represent access is error ~%:p_td
} F-,{+B66
@CI6$
GiwA$^Hg\
String sHeader; _1c_TMh}9
V"jnrNs3
5g>kr<K
for(int i=1;;i++) >b?)WNk
{ z ;Nk& <?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R./6Q1
//Utility.log(in.readLine()); {1DYXKe
sHeader=httpConnection.getHeaderFieldKey(i); jF_I4H
if(sHeader!=null) ",V5*1w
{ iQ"F`C
if(sHeader.equals("Content-Length")) ~WXxVm*@
{ }V;]c~Q/H
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K.1yncS^
break; slfVQ809
} (b}7Yb]#c
} H^:|`T|,
else O~'yP@&`
break; J\D3fh97-
} bu&y w~
} X2?_lZ[\
catch(IOException e){e.printStackTrace ();} a`iAA1HJ
catch(Exception e){e.printStackTrace ();} W(4?#lA2W
" z'!il#
BQ0\+
Utility.log(nFileLength); :Ia&,;Gc
=T}uQ$X
J4#]8!A
return nFileLength; xumv I{
} "1Aus
8mLU ~P |
(#M$t!'%
//保存下载信息（文件指针位置） G@!9)v]9
private void write_nPos() 1^^D :tt
{ S Tk#hhx
try{ >D62l*VC)
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1tz .e\
output.writeInt(nStartPos.length); 1u+(rVQN
for(int i=0;i<nStartPos.length;i++) fGWK&nONyk
{ T["(YFCByg
// output.writeLong(nPos); P[8N58#
output.writeLong(fileSplitterFetch.nStartPos); nn%xN\~<
output.writeLong(fileSplitterFetch.nEndPos); D~&e.y/gHN
} &~f_1<
output.close(); bR,Iq}p
} JhIK$Ti
catch(IOException e){e.printStackTrace ();} p;=(-4\V}
catch(Exception e){e.printStackTrace ();} (k&aD2PH
} 0*@S-Lj^c
D+""o"%
5K~6`
//读取保存的下载信息（文件指针位置） Ib2pV2`h(
private void read_nPos() |R/50axI
{ AB\4+ CLV
try{ n5>N9lc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZS_f',kE
int nCount = input.readInt(); Z"+!ayA7D
nStartPos = new long[nCount]; oF xVK
nEndPos = new long[nCount]; k"{U}Y/}
for(int i=0;i<nStartPos.length;i++) V7_??L%Ct`
{ <5~>.DuE
nStartPos = input.readLong(); 4HE4e
nEndPos = input.readLong(); +'.Q-
} hj,x~^cS
input.close(); |?A-?-
} 0+pJv0u
catch(IOException e){e.printStackTrace ();} I0RWdOK8K
catch(Exception e){e.printStackTrace ();} dxWw%_Q
} = g}yA=.
=LnAMl#9
]]3D` F}
private void processErrorCode(int nErrorCode) -1JHhRr]
{ u`|fmVI
System.err.println("Error Code : " + nErrorCode); A,qG*lv
} B4aZ3.&W
3/FB>w gt
Kjw\SQ)2~
//停止文件下载 hhhO+D1(
public void siteStop() e r$'c
{ GK&Dd"v
bStop = true; E76:}(
for(int i=0;i<nStartPos.length;i++) BUyA]
fileSplitterFetch.splitterStop(); --kK<9J7
sKO ;p
)zo ;r!eP
} '%N)(S`O7P
} KL4/"$l]
//负责部分文件的抓取 Q@n kT1o
**FileSplitterFetch.java "g-NUl`'
*/ !&[4T#c
package NetFox; N<99K!
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gBu4`M
import java.io.*; lV'83
import java.net.*; =w-H )
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public class FileSplitterFetch extends Thread { 2-84
mX^RSg9E}
zn|}YovY+
String sURL; //File URL 5Y^YKV{
long nStartPos; //File Snippet Start Position )3sb2 #
long nEndPos; //File Snippet End Position mN02T@R-
int nThreadID; //Thread's ID za7wNe(s
boolean bDownOver = false; //Downing is over _wCSL.
boolean bStop = false; //Stop identical W6Pg:Il7
FileAccessI fileAccessI = null; //File Access interface C.<4D1}P
X)m2{@v D
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g\'sGt3O
{ 2|BE{91
this.sURL = sURL; -;}Wm[
this.nStartPos = nStart; 6EY4@0%A
this.nEndPos = nEnd; c&&UT-Z
nThreadID = id; #Gx@\BE{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X;h~s:LM
} y1X.Mvc
~_%[j8o&l
pG&.Ye]j
public void run() M .,|cx
{ 2uIAnbW]M
while(nStartPos < nEndPos && !bStop) FhGbQJ?[3
{ Q*: Ow]
*F0N'*
iQF93:#
try{ 9[Mu
URL url = new URL(sURL); jLTs1`I/F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D$HxPfDZ
httpConnection.setRequestProperty("User-Agent","NetFox"); zeX?]@]Y
String sProperty = "bytes="+nStartPos+"-"; GCHssw~P'v
httpConnection.setRequestProperty("RANGE",sProperty); .+yJ'*i$d
Utility.log(sProperty); <FEO6YP
71_N9ub@z
q9Q4F
InputStream input = httpConnection.getInputStream(); Q"O _h
//logResponseHead(httpConnection); A\`Uu&
G1rgp>m
dkjL;1
byte[] b = new byte[1024]; Jp- hFD
int nRead; }R^{<{KVJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {`VQL6(i
{ h.nzkp5
nStartPos += fileAccessI.write(b,0,nRead); !?{5ET,gtN
//if(nThreadID == 1) N*fN&0r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?=/l@d
} VMp6s%m
+Ji dP
*L=CJg
Utility.log("Thread " + nThreadID + " is over!"); v&Kw 3!X#E
bDownOver = true; eC?N>wHH
//nPos = fileAccessI.write (b,0,nRead); /1*\*<cs
} _N6GV$Q
catch(Exception e){e.printStackTrace ();} ~&kV
} TUG3#PSnm*
} Mtu8zm
x)*[>d2yd
rlD@O~P4
//打印回应的头信息 Ch3##-
public void logResponseHead(HttpURLConnection con) 8QU`SoS9
{ EOL03N
for(int i=1;;i++) Jy9&=Qh
{ 3I]5DW %-
String header=con.getHeaderFieldKey(i); ]#`bYh^y
if(header!=null) j.o)!SA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y^ohns5{
Utility.log(header+" : "+con.getHeaderField(header)); 7L)edR[
else BWRAz*V
break; iZm# "}VG
} 4LO4SYW7
} YW9r'{(D(I
B8_)I.
WZ,}]D
public void splitterStop() Vz_ac vfk^
{ dp;;20z
bStop = true; IsP-[0it
} J8IdQ:4^l
P5-1z&9O
0se0AcrW
} x\0(l5>
j=c=Pe"?u
jT/}5\
/* ;J[ed>v;3
**FileAccess.java /q[5-96c
*//文件访问(定位，写) <j\osw1R
package NetFox; max 5s$@
import java.io.*; {P/ sxh:e
/,Unp1D
*WTmS2?'h
public class FileAccessI implements Serializable{ *XN|ZGl/
[=/Yo1:v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9NzK1V0X
RandomAccessFile oSavedFile; ;6+e!h'1
long nPos; =T7lv%u
pAK7V;sJ
PH!^ww6
public FileAccessI() throws IOException zt,Tda4Y
{ j`H5S
this("",0); e *9c33
} -!_\4
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public FileAccessI(String sName,long nPos) throws IOException U-h'a: K
{ ^v2-"mX<
oSavedFile = new RandomAccessFile(sName,"rw"); Dqxtc|vo
this.nPos = nPos; A8|DB@Bi
oSavedFile.seek(nPos); nrFuhW\r
} J]h$4"
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ko7*9`
public synchronized int write(byte[] b,int nStart,int nLen) [l`_2{:
{ >{/As][
int n = -1; lRO7 Ae
try{ %KjvV<f-a
oSavedFile.write(b,nStart,nLen); :6h$1 +6
n = nLen; WRdBL5
} $~^Y4 } m
catch(IOException e) <t~RGn3
{ k 'CM^,F&
e.printStackTrace (); P }BU7`8
} fC4#b?Q
Nd;)V
lhk=yVG3
return n; 8?yRa{'"
} WSi`KNX
:NCY6? [Dz
s8O.yL
} (Ci{fY6`
!<EQVqj6
pwIu;:O!?
/* At t~NTL
**SiteInfoBean.java A vh"(j
*/ &7 0o4~Fr
package NetFox; ~k(4eRq
3AQu\4+A
a ](Jc)
public class SiteInfoBean { 2bnF#-(
DTx!# [
(9!/bX<
private String sSiteURL; //Site's URL Q`0k=<
private String sFilePath; //Saved File's Path dRhsnT+KX
private String sFileName; //Saved File's Name s3Wjg
private int nSplitter; //Count of Splited Downloading File 0`H)c) pP
eV"Za.a.
U??T>
public SiteInfoBean() =!R+0
{//nSplitter的缺省值为5 arQEi
//default value of nSplitter is 5 vG2&qjY1
this("","","",5); :c?}~a~JO(
} U%PII>s'#
Y%GIKtP
fR^aFT
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :nLhg$wMs
{ Yw!(]8PYdU
sSiteURL= sURL; >}I BPC
sFilePath = sPath; Ho^rYz
sFileName = sName; 2a,l;o$2&
this.nSplitter = nSpiltter; n){F FM
)@hG#KMK
^Gt9.
} n !oxwA!
_=g;K+%fb
GEd JB=
public String getSSiteURL() 2D vKW%;
{ HLruZyN4
return sSiteURL; J]"IT*-Ht
} C)H1<Br7
&pk&8_=f
4Yx\U
public void setSSiteURL(String value) 13f@Ox$
{ z>&|:VGG
sSiteURL = value; CHGV1X,
} 9{(A-
qiyX{J7Z
wMx#dP4W8
public String getSFilePath() wU $j/~L
{ rL9u7)x
return sFilePath; I<}<!.Bc!
} 24; BY'
4xl}kmvv
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public void setSFilePath(String value) [(d))(M$|
{ w1q`
sFilePath = value; 8~6H\.0Q
} AzlZe\V?)~
&?wNL@n
*$6dNx
public String getSFileName() 2*5]6B-(
{ +T,Yf/^Fn
return sFileName; 8 mFy9{M
} [>#@?@x`P
+C8yzMN\
y<0RgG1qp
public void setSFileName(String value) fvH4<c5x
{ /ZpwJc`e
sFileName = value; m&&Y=2
} 4eh~/o&h
83[gV@LW0m
9=FqI50{
public int getNSplitter() >dU.ic?19
{ .9'bi#:Cw
return nSplitter; Zp'q;h_
} t7; ^rk*
c1>:|D7w
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public void setNSplitter(int nCount) ~REP@!\r^
{ D$&LCW#x
nSplitter = nCount; ~bsL W:.'
} CA8N
} 8-.jf
X) O9PQ
: l&g5
/* A."]6R<
**Utility.java YZllfw$9
*/ 9~Ve}NB#z&
package NetFox; Ee0}Xv
`=FDNOwp
y'#i'0eeL
public class Utility { PrwMR_-
-s5>GwZt
2"IsNbWV
public Utility() hF4gz*Q
{ E2%{?o
27CVAX ghV
898=9`7e
} \'[C_+;X
5<=ktA48[
//线程睡眠 W%,h{
public static void sleep(int nSecond) FsTl@zN
{ J~=tR1k
try{ 23_\UTM}1
Thread.sleep(nSecond); Dc;zgLLL
} 78n`VmH~L
catch(Exception e) ^PrG5|,s
{ x |0@T?
e.printStackTrace (); YI!@,t
} p+7ZGB
} KvtX>3#qM
PD$@.pib
//日志 iLR^V!
public static void log(String sMsg) PEIf)**0N
{ KsR^:_e
System.err.println(sMsg); lQ!)0F
} hOH DXc"
v[t*CpGd
Q/u1$&1
public static void log(int sMsg) Bq 9Eu1
{ m:4Ec>?e
System.err.println(sMsg); c*:H6(u
} ?jy6%Y#,i
} ek9Y9eJ"
uL1$yf'
![}q9aeT
/* ,LpGE>s
**TestMethod.java P S [ifC
*/ s?-J`k~q
package NetFox; 25m6/Y
Sru}0M#M
W2-1oS~ma
public class TestMethod { BH+@!H3hf
d4[mR~XXT
^Ox|q_E w}
public TestMethod() LkA_M'G
{ ///xx/weblogic60b2_win.exe U)B^R
try{ a-(OAzQ_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hnD=DLW $
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); S{.G=O
SiteFileFetch fileFetch = new SiteFileFetch(bean); uU;]/
fileFetch.start(); N sNk
} 8"5^mj
catch(Exception e){e.printStackTrace ();} ;wF 0s
t.YY?5l
`:y {
} DuV@^qSbG.
AQR/nWwx
"oc&uj
public static void main(String[] args) QO|roE
{ lf?dTPrD
new TestMethod(); OqNtTk+
} J=@D]I*3
} ']cRSj.
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