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)); ;Q\MH t*
} 6Ij'z9nJw
for(int i=0;i<nEndPos.length-1;i++) ;Z!x\{-L
{ 9^g?/8
nEndPos = nStartPos[i+1]; I4(z'C
} 2F#DJN#
nEndPos[nEndPos.length-1] = nFileLength; +<rWYF(ii/
} pKkBAr,
} 1w}DfI
T )!kJ;vc
uy rS6e0
//启动子线程 w^E$R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; HyC826~-rI
for(int i=0;i<nStartPos.length;i++) @&9,0x
{ RfQ*`^D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TxP8&!d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _"h1#E
nStartPos,nEndPos,i); ICD;a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -jk-ve
fileSplitterFetch.start(); =`E{QCW
} Ft<B[bQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :rSCoi>K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~%!"!Z4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |Sr
nEndPos = " + nFileLength); ('1]f?:M
// fileSplitterFetch[nPos.length-1].start(); "'*Qq@!3?
W0k7(v)
m8<.TCIQ
//等待子线程结束 %`\=qSf*
//int count = 0; Wa<SYJ
//是否结束while循环 Lk2;\D>
boolean breakWhile = false; "U|u-ka8B
:wY(</H
v{;^>"5o
while(!bStop) P2fiK
{ Kr%w"$<
write_nPos(); J936o3F_
Utility.sleep(500); tJII-\3"
breakWhile = true; J0FJ@@
L XHDX
h@jk3J9^
for(int i=0;i<nStartPos.length;i++) d8J(~$tXQN
{ guk{3<d:Jy
if(!fileSplitterFetch.bDownOver) q);@iiJ-
{ zbAyYMtEk
breakWhile = false; Mz: "p.
break; S!8q>d,%L
} !SdP<{[
} 8A: =#P^O\
if(breakWhile) :&J1#% t
break; ,'%*z
pM}n)Q!{3"
'.*`PN5mDq
//count++; #ba7r ]Xu
//if(count>4) ?wpl 88z
// siteStop(); ImsyyeY]
} ypWhH
-\~HAnh
~;vt{pk
System.err.println("文件下载结束！"); >D_!d@Z
} Q(jIqY1Hf
catch(Exception e){e.printStackTrace ();} A`nzqe#(1
} =3|5=ZU034
h3j`X'
Oid;s!-S6
//获得文件长度 O #5`mo
public long getFileSize() r#NR3_@9
{ sI`oz|$
int nFileLength = -1; j>A=Wa7
try{ |Ge!;v
URL url = new URL(siteInfoBean.getSSiteURL()); ?*:BgaR_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1pM>-"a8j
httpConnection.setRequestProperty("User-Agent","NetFox"); BHpj_LB-P
r#B{j$Rw
juEH$7N!
int responseCode=httpConnection.getResponseCode(); $GQ{Ai:VwF
if(responseCode>=400) />O.U?
{ FL[w\&fp
processErrorCode(responseCode); Zb:S IJ
return -2; //-2 represent access is error ]%Lk#BA@A
} KqvM5$3
ld7B{ ?]
kiu#THF
String sHeader; ^zKP5nzL
H=6-@+ !o
jH[{V[<#X
for(int i=1;;i++) 7~H"m/;U&
{ Q1RUmIe_&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,'byJlw_pv
//Utility.log(in.readLine()); zcOG[-
sHeader=httpConnection.getHeaderFieldKey(i); q OV$4[r
if(sHeader!=null) VLC=>w\,
{ <x1,4a~
if(sHeader.equals("Content-Length")) #YK=e&da
{ tS[%C)
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); E&0]s
break; naM=oSB(
} Qn \=P*j
} Z9zsvg
else ~Gh9m]b
break; ,e{1l
} WD|pG;Gq
} X4/3vY
catch(IOException e){e.printStackTrace ();} Kza5_7p`L
catch(Exception e){e.printStackTrace ();} _uZVlu@
+<'>~lDg
hy"=)n(
Utility.log(nFileLength); YbJB.;qK
r TK)jxklX
Vkl]&mYRz
return nFileLength; rQ)I
} /gP"X1.
m0]Lc{
1 Ay.^f
//保存下载信息（文件指针位置） KNSMx<GP
private void write_nPos() $u, ~183
{ p*|Ct
try{ 8r.3t\o)X
output = new DataOutputStream(new FileOutputStream(tmpFile)); Yq%r\[%*
output.writeInt(nStartPos.length); Ur(< ]
for(int i=0;i<nStartPos.length;i++) RpzW-
{ 6A-nhvDP
// output.writeLong(nPos); QxiAC>%K
output.writeLong(fileSplitterFetch.nStartPos); i}~U/.P
output.writeLong(fileSplitterFetch.nEndPos); \N.Bx
} 'h>CgR^NM1
output.close(); gP?.io9Oi
} wj\kx\+
catch(IOException e){e.printStackTrace ();} \;0UP+
catch(Exception e){e.printStackTrace ();} }T"&4Rvs2R
} v\-7sgZR
KA elq*
VujIKc#4
//读取保存的下载信息（文件指针位置） m">2XGCn
private void read_nPos() i)@H
{ `Gh#2U
try{ ,p6o "-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gt!tDu
int nCount = input.readInt(); 7w?N-Q$y
nStartPos = new long[nCount]; G],W{<Pe
nEndPos = new long[nCount]; |t_SN,)dd
for(int i=0;i<nStartPos.length;i++) Q\aC:68
{ ),Igu
nStartPos = input.readLong(); q}hHoSG]=
nEndPos = input.readLong(); ADB,gap
} v|:TYpku3
input.close(); nw=:+?
} ZX0!BS
catch(IOException e){e.printStackTrace ();} T_oL/x_;
catch(Exception e){e.printStackTrace ();} M! uE#|
} lGX8kAv?
K*N8Vpz(
[q~3$mjQ
private void processErrorCode(int nErrorCode) _aw49ag;
{ oI x!?,1
System.err.println("Error Code : " + nErrorCode); ]>,Lw=_[_
} ,Ofou8C6
GhW{6.^
d8VFa'|
//停止文件下载 b\C1qM4
public void siteStop() 4GexYDk'#
{ `Lr|KuFN
bStop = true; @O HsM?nW
for(int i=0;i<nStartPos.length;i++) Gy!bPVe
fileSplitterFetch.splitterStop(); h/7_IuD
a4eE/1
) -@Dh6F
} #g]eDU-[
} hv)d
//负责部分文件的抓取 mf\@vI
**FileSplitterFetch.java BHDd^bd
*/ x%55:8{
package NetFox; tF!-}{c"k
S=3H.D!f
,m;G:3}48
import java.io.*; E*83N@i
import java.net.*; m>+e;5
/}=cv>S5V
EkEQFd 5g
public class FileSplitterFetch extends Thread { >7 qZ\#
p&ZLd`[
S=X_7V
String sURL; //File URL yOyuMZo6
long nStartPos; //File Snippet Start Position Y|aaZ|+
long nEndPos; //File Snippet End Position |],ocAN{
int nThreadID; //Thread's ID jiP^Hz"e
boolean bDownOver = false; //Downing is over %R?#Y1Tq;
boolean bStop = false; //Stop identical HQ^:5XH
FileAccessI fileAccessI = null; //File Access interface o_PQ]1
D>K=D"
K<fB]44Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'V}4_3#q
{ 9tIE+RD
this.sURL = sURL; WP4"$W
this.nStartPos = nStart; ,pa=OF
this.nEndPos = nEnd; #A^(1
nThreadID = id; J;Eg"8x]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 g>-u9%aa
} Yn8aTg[J
$i$Z+-W4'
U9h@1:
public void run() >{#QS"J#
{ nw
while(nStartPos < nEndPos && !bStop) -\M;bQV[C
{ xd^9R<
R9InUX"k
UKf0cU
try{ I->4Q&3
URL url = new URL(sURL); ]SNcL[U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w'<"5F`
httpConnection.setRequestProperty("User-Agent","NetFox"); S3?U-R^`
String sProperty = "bytes="+nStartPos+"-"; 9/6=[)
httpConnection.setRequestProperty("RANGE",sProperty); I|)U>bV
Utility.log(sProperty); AHn Yfxv_
z:JJ>mxV
SHN'$f0Mb
InputStream input = httpConnection.getInputStream(); }&LLo
//logResponseHead(httpConnection); ^4{"h
myDcr|j-a
8J8@0
byte[] b = new byte[1024]; N@\`DO
int nRead; io*iA<@Gx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Dh .<&ri
{ m]'P3^<{P
nStartPos += fileAccessI.write(b,0,nRead); n!%'%%o2v
//if(nThreadID == 1) X!f` !tZ:{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9oxn-)6JC
} qp2&Z8S\D
&#<>fT_
O 718s\#
Utility.log("Thread " + nThreadID + " is over!"); w>6cc#>q
bDownOver = true; q 1+{MPJ
//nPos = fileAccessI.write (b,0,nRead); 4_h?E:sBb
} KNqs=:i
catch(Exception e){e.printStackTrace ();} X>ck.}F
} '%[r9w
} iU?xw@WR
v)rQ4 wD:
7oZtbBs]M
//打印回应的头信息 p/'09FY+U
public void logResponseHead(HttpURLConnection con) Ll0"<G2t
{ !Bn,f2
for(int i=1;;i++) }Z8DVTpX}
{ L] !M1\
String header=con.getHeaderFieldKey(i); $;B0x
if(header!=null) 9M1UkS$`@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |M(0CYO
Utility.log(header+" : "+con.getHeaderField(header)); Ae>:i7.V
else utBKl'`
break; @Jr@ fF}
} )jed@?
} XJZS}Z7h
& _mp!&5XV
YQ7tZl;:t
public void splitterStop() E{}Vi>@V?
{ QZamf lk
bStop = true; e\'=#Hw
} >2dF^cDE-3
MUvgmJsN
=;y(b~
} R6-Z]Hu
3Tz~DdB
[.c'22R6
/* >IE`, fe
**FileAccess.java ($[)Tcq*~
*//文件访问(定位，写) F]6$4o[
package NetFox; W,ik ;P\
import java.io.*; %S]g8O[}nl
w~}.c:B
oO][X
public class FileAccessI implements Serializable{ >PoVK{&y
(K3eb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5nv1%48Ri
RandomAccessFile oSavedFile; A,]%*kg2
long nPos; c,_??8
)@a_|q@V
<K GYwLk
public FileAccessI() throws IOException Vc$y^|=
{ {q|Om?@
this("",0); EN{o3@ O'
} ":V,&o9n
@szr '&\%A
.lyK ,p
public FileAccessI(String sName,long nPos) throws IOException pW1(1M)[%Z
{ 8N9X1Mb|
oSavedFile = new RandomAccessFile(sName,"rw"); ^2-t|E=
this.nPos = nPos; *g!7PzJ'
oSavedFile.seek(nPos); #D|n6[Y'.t
} g~]?6;uu
\TnRn(Kw
%#iu
public synchronized int write(byte[] b,int nStart,int nLen) pT'jX^BU
{ O7lFg;9c`
int n = -1; -8m3L
try{ yNOoAnGT W
oSavedFile.write(b,nStart,nLen); 2C"[0*.[N
n = nLen; s0*@zn>h
} 67T=ku
catch(IOException e) oxXCf%!
{ l" +q&3Zx
e.printStackTrace (); @~8*
} _BHEK
tzrvIVD
V?&P).5)
return n; ]3]=RuQK2
} =SVb k
)%vnl~i!
ch]{=61
} 'T(@5%Db
9A ?)n<3d
5]~451
/* ?tx."MZ
**SiteInfoBean.java P$5K[Y4f
*/ QJ2D C
package NetFox; /_</m?&.U&
()e|BFL.
Fx )BMP
public class SiteInfoBean { /X%+z5
ip!-~HNwJ
}56WAP}Z 4
private String sSiteURL; //Site's URL Fs&r^ [/b
private String sFilePath; //Saved File's Path b)@rp
private String sFileName; //Saved File's Name q![`3m-d.
private int nSplitter; //Count of Splited Downloading File B}0!b7!
}/2M?W0
i>e?$H,/
public SiteInfoBean() z]R%'LGu
{//nSplitter的缺省值为5 Q)=LbR{#
//default value of nSplitter is 5 }CL7h;5N 3
this("","","",5); tE,& G-jU
} GA;h7
`T{'ufI4B
LkXho>y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Lg{M<Q)4
{ qHnX)
sSiteURL= sURL; 1Eb2X}XC
sFilePath = sPath; nF$HWp&gt
sFileName = sName; q _Z+H4
this.nSplitter = nSpiltter; 9}5o> iR
V!/9GeIF
rn/~W[
} HoK+g_9~
p<3<Zk 7~0
+lxjuEiae
public String getSSiteURL() SDB \6[D
{ M.+h3<%^
return sSiteURL; <w`EU[y_
} $ ^@fV=e
E^A S65%bL
Ec@cW6g(%
public void setSSiteURL(String value) FzNj':D
{ W^)mz,%x
sSiteURL = value; HQ]mDo
} |Z)}-'QUJ
]|tR8`DGZ%
d::9,~
public String getSFilePath() H]7bqr
{ "=1gA~T
return sFilePath; @yo6w}3+-
} wl&T9O;?
3dlY_z=0
v>j,8E
public void setSFilePath(String value) b$yIM
{ %}e['d h
sFilePath = value; uVKe?~RC
} S~)`{ \
<bb!BS&w
?|98Y"w
public String getSFileName() 3n)$\aBE
{ FvY=!U06
return sFileName; *5.wwV
} 1DcX$b
mt$rjk=
:9av]Yv&
public void setSFileName(String value) ar#73f
{ 3E^qh03(
sFileName = value; : NA(nA 3
} ZE-vroh
yo/;@}g}
Km $o@
public int getNSplitter() 1Y*k"[?dW
{ Kei0>hBi
return nSplitter; |9=A"092{
} fLqjBG]<
3]GMQA{L)
LWm1j:0
public void setNSplitter(int nCount) ]J'TebP=L5
{ 5!fOc]]Ow
nSplitter = nCount; Sc/l.]k+
} ah hl
} LXh}U>a9
ge1. HG
Jw8?o/1D@
/* ]95VMyN
**Utility.java NIVR;gm
*/ NS2vA>n8R
package NetFox; nAWb9Yk
38D5vT)n
L7;~4_M9.V
public class Utility { [U/h'A.j
:>JfBJ]|
^;<d<V}*
public Utility() hdCd:6
{ d}zh.O5P!
&`@YdZtd"
$QwpoVp`~
} Q&xH
~Ym_ {
//线程睡眠 CTW\Dt5
public static void sleep(int nSecond) cJaA*sg
{ ;7qIm83
try{ TT/H"Ri}Jp
Thread.sleep(nSecond); =Q40]>bpx
} q+\<%$:u
catch(Exception e) P?/JyiO}
{ 9>w~B|/
e.printStackTrace (); FHQ`T\fC$@
} TPJF?.le '
} `!Z?F]):G
'~&W'='b;
//日志 ?-<lIFFh
public static void log(String sMsg) }6%XiP|
{ (T#$0RFq
System.err.println(sMsg); I?}jf?!oM
} KhfADqji|
h'-4nu;*
'Gl~P><e
public static void log(int sMsg) MSQ^ovph
{ o'$"MC+
System.err.println(sMsg); *^|\#UIk
} g77M5(ME
} ~dr,;NhOLJ
U_"!\lI_yg
dYrgL3'
/* VQHB}Y@^
**TestMethod.java F)hj\aHm k
*/ /ovVS6Ai
package NetFox; S{;Pga*Px
b!@PS$BTxq
~r.R|f]IQ
public class TestMethod { >n09K8 A
TM(y%!\
Njg$~30
public TestMethod() P0.cF]<m
{ ///xx/weblogic60b2_win.exe "TJu<O"2
try{ rpRyB9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =:s`C,l.4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m>vwpRBOA
SiteFileFetch fileFetch = new SiteFileFetch(bean); "V>}-G&
fileFetch.start(); t<##0#xS.
} Qjfgxy]
catch(Exception e){e.printStackTrace ();} 8D )nM|
w1)TnGT
Z&n[6aV'F
} T o["o!(;z
TF/NA\0c$
]#]Z]9w
public static void main(String[] args) eK:?~BI!
{ {1Ra|,;
new TestMethod(); h~k<"
} Gw<D'b)!
} f#!+l1GV
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