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)); 9LC&6Q5O&
} xg@NQI@7
for(int i=0;i<nEndPos.length-1;i++) ),}AI/j;zY
{ ?/hZb"6W
nEndPos = nStartPos[i+1]; yR5XJ;Tct
} SkQswH
nEndPos[nEndPos.length-1] = nFileLength; EbNd=Z'J
} pc]J[ S?P
} XRN+`J
^Q<mV*~
Wi.5Y{
//启动子线程 @C_KV0i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )FN;+"IJ
for(int i=0;i<nStartPos.length;i++) KJn!Ap
{ e.d #wyeX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bpAv1udX-W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $tqJ/:I
nStartPos,nEndPos,i); \c,pEXG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I{'f|+1
fileSplitterFetch.start(); qy1F*kY
} &<TzGB*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Hy:V`>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YIhm$A"z0"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2-*V=El
nEndPos = " + nFileLength); J5Z%ImiT^O
// fileSplitterFetch[nPos.length-1].start(); ^ <`(lyph
Jb_1LZ)]
u^Ku;RQo
//等待子线程结束 Uh eC
//int count = 0; PXoz*)tk
//是否结束while循环 :(|'S4z
boolean breakWhile = false; E_z;s3AXQ
@oP_;G
#65^w=Sp}
while(!bStop) {@Yb%{+
{ B_`y|sn
write_nPos(); IA zZ1#/3
Utility.sleep(500); +gd2|`#
breakWhile = true; ^>x|z.
qVqRf.-\
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for(int i=0;i<nStartPos.length;i++) -/C)l)V}
{ O43YY2
if(!fileSplitterFetch.bDownOver) ^[E'1$D
{ Ox!U8g8c
breakWhile = false; LWoG4s?w
break; h5_G4J{1
} 0-Y:v(|.
} +yob)%
if(breakWhile) O=cxNy-I
break; ,fDEz9-,
`^JJ&)4iv
4BYE1fUzd
//count++; EI>6Nh
//if(count>4) %=we`&
// siteStop(); '7Nr8D4L
} Cb t{H}I3
'+>fFM,*B
F7L&=K$2y
System.err.println("文件下载结束！"); 7M_U2cd|TD
} gbeghLP[?
catch(Exception e){e.printStackTrace ();} YpAg
} |'ln?D:&
8b.u'r174
WW2Ob*
//获得文件长度 ?<&O0'Q
public long getFileSize() kqYa*| l
{ fA%z*\
int nFileLength = -1; yq-=],h
try{ 5RH2"*8T
URL url = new URL(siteInfoBean.getSSiteURL()); >Iewx Gb>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,Y?sfp
httpConnection.setRequestProperty("User-Agent","NetFox"); =\#%j|9N9
{gA\ph%s
sbkQ71T:
int responseCode=httpConnection.getResponseCode(); }eQRN<}P
if(responseCode>=400) iB0WEj[?
{ ,r^M?>
processErrorCode(responseCode); r"2V
return -2; //-2 represent access is error \I-#1M
} TC~Q G$NW
ne61}F"E
87)zCq
String sHeader; /){KOCBl;
)Au6Nf
"vCM}F
for(int i=1;;i++) #*$P'r
{ (iJ1 ;x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5J)=}e
//Utility.log(in.readLine()); q+KzIde|%
sHeader=httpConnection.getHeaderFieldKey(i); "LYh7:0s!k
if(sHeader!=null) R3)57OyV
{ Q-Ux<#
if(sHeader.equals("Content-Length")) \l"&A
{ ?&LZB}1R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); s](aNe2j
break; _zt19%Wg
} fJ\sguZ
} C3hv*
else x^|Vaf
break; IEjP<pLe
} O1 .w,U
} <^b7cOFQ
catch(IOException e){e.printStackTrace ();} G2LK]
catch(Exception e){e.printStackTrace ();} KfBTL!0#
i&njqK!wS
'}g*!jL
Utility.log(nFileLength); o-xDh7v
^_5L"F]sP
lZ8CY
return nFileLength; pME{jD
} O%1v)AT&\
*19ax&|*S
,\ 2a=Fp
//保存下载信息（文件指针位置） tx"sH]n
private void write_nPos() -U<Upn)2
{ 6{[pou&
try{ "G-1>:
output = new DataOutputStream(new FileOutputStream(tmpFile)); fP3_d
output.writeInt(nStartPos.length); B63pgPX
for(int i=0;i<nStartPos.length;i++) lPLz@Up~
{ ze_{=Cv&Y
// output.writeLong(nPos); OA:%lC!
output.writeLong(fileSplitterFetch.nStartPos); VIP7OHJh
output.writeLong(fileSplitterFetch.nEndPos); KZ!3j_pKy
} DjU9 uZT
output.close(); J};z85B
} +(xeT+J
catch(IOException e){e.printStackTrace ();} -p-B2?)A
catch(Exception e){e.printStackTrace ();} `X,yM-(
} +\li*G]:J
#`GY}-hL!
!R*-R.%
//读取保存的下载信息（文件指针位置） Q^p|Ldj
private void read_nPos() h/x0]@M&
{ @i^~0A#q*
try{ p^(&qk?ut
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ut>4U'.H
int nCount = input.readInt(); v7%X@j]ji
nStartPos = new long[nCount]; 5L:1A2Z?c
nEndPos = new long[nCount]; |AlR^N
for(int i=0;i<nStartPos.length;i++) e*+FpW@
{ [4fU+D2\d
nStartPos = input.readLong(); iK?b~Q
nEndPos = input.readLong(); i,13b e
} [1Ydo`
input.close(); &V|>dLT>A
} 3nY1[,
catch(IOException e){e.printStackTrace ();} tbnH,*
catch(Exception e){e.printStackTrace ();} ~gz^Cdh
} JFgoN,xn
Bl9jkq ]
iHf-{[[Z
private void processErrorCode(int nErrorCode) {pb>$G:gfx
{ =AVgIv
System.err.println("Error Code : " + nErrorCode); :V2bS
} a[lY S{
R<i38/ ~G
8Ld:"Y#
//停止文件下载 &V>fYgui
public void siteStop() !v]b(z`Y
{ %{6LUn
bStop = true; OMwsbp&
for(int i=0;i<nStartPos.length;i++) 7Cjd.0T=(
fileSplitterFetch.splitterStop(); lTU$0CG
'qdPw%d
2,aPr:]
} IrMl:+t\
} RE.r4uOJg
//负责部分文件的抓取 uxg9yp@|
**FileSplitterFetch.java X0-IRJ[
*/ v(OBXa9
package NetFox; FgL,k
X-Wz:NA
y*{Zbz#{
import java.io.*; Rl|4S[
import java.net.*; [i0Hm)Bd3
k%y9aO
T0)"1D<l
public class FileSplitterFetch extends Thread { _LwOOZj
vIvVq:6_3
EQqx+J&!
String sURL; //File URL kY]W Qu
long nStartPos; //File Snippet Start Position jlFk@:y4
long nEndPos; //File Snippet End Position !ZDzEP*
int nThreadID; //Thread's ID m\/ Tj0e
boolean bDownOver = false; //Downing is over O4<g%.HC6
boolean bStop = false; //Stop identical Ev!{n
FileAccessI fileAccessI = null; //File Access interface @|a>&~xX
P;PQeXKw
iR$<$P5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException K^r)CCO
{ 7u\*_mrv
this.sURL = sURL; x\2?ym@
this.nStartPos = nStart; GRy-+#,b"
this.nEndPos = nEnd; Ifk#/d
nThreadID = id; s] /tYJYl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7VK}Dy/Vvn
} .oEmU+
X0{/ydGF8
1_$xSrwcF
public void run() nN$Y(2ZN
{ uS&|"*pR
while(nStartPos < nEndPos && !bStop) Ax oD8|
{ 6 \B0^
@DW[Z`X
OL7_'2_z.
try{ HE<1v@jW
URL url = new URL(sURL); ,:+dg(\r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +.RKi!
httpConnection.setRequestProperty("User-Agent","NetFox"); ]4+s$rG
String sProperty = "bytes="+nStartPos+"-"; PL{Q!QJK'
httpConnection.setRequestProperty("RANGE",sProperty); 74<!&t
Utility.log(sProperty); PNW \*;j
TwyM\9l7
'gQidf
InputStream input = httpConnection.getInputStream(); EL3|u64GO
//logResponseHead(httpConnection); @v\*AYr'M
q.Nweu!jQ
@?C#r.vgp
byte[] b = new byte[1024]; * y^OV_n-8
int nRead; ,2oF:H
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R~bC,`Bh
{ c62=*] ,
nStartPos += fileAccessI.write(b,0,nRead); HaA1z}?n
//if(nThreadID == 1) = sAn,ri
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p8wyEHB
} D+lzFn$3
M>jtFP<S
3Q/#T1@
Utility.log("Thread " + nThreadID + " is over!"); {;2i.m1
bDownOver = true; $-+/$!
//nPos = fileAccessI.write (b,0,nRead); \b}~2oX
} MH|]\
catch(Exception e){e.printStackTrace ();} MJj4Hd
} {F&-7u0
} >-E<n8
,_!6U
R`F,aIJ]
//打印回应的头信息 `k\grr.J
public void logResponseHead(HttpURLConnection con) Es5
{ KCe13!
for(int i=1;;i++) |L_wX:d`9
{ uGdp@]z&8Q
String header=con.getHeaderFieldKey(i); doHF|<s
if(header!=null) 5>9Y|UU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JT[*3h
Utility.log(header+" : "+con.getHeaderField(header)); t+CWeCp,
else T5wjU*=IL
break; EoX_KG{
} dQy>Nmfy
} wx=0'T-[
=1dI>M>tm
^s\3/z>b4!
public void splitterStop() qdCWy
{ 9Qj2W
bStop = true; {#IPf0O
} CeT~p6=
mq/zTm
"S~_[/q
} (_* wt]"'
]43[6Im
_9:@Vl]Q@
/* KsAH]2Q%
**FileAccess.java PXP`ZLF
*//文件访问(定位，写) ')+0nPV
package NetFox; O?bK%P]ay
import java.io.*; m9M FwfZ
7#;vG>]
X7UBopm&
public class FileAccessI implements Serializable{ EjEFg#q
<<MjC5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]O:M$ $
RandomAccessFile oSavedFile; ps1YQ3Ep&
long nPos; L{gE'jCC
,xJrXPW
rl:KJ\*D
public FileAccessI() throws IOException b syq*
{ $awi>#[
this("",0); 1;u4X`8
} K0+;bu
"cho }X
lD;'tqaC
public FileAccessI(String sName,long nPos) throws IOException _17|U K|N
{ uK*Nu^
oSavedFile = new RandomAccessFile(sName,"rw"); BpAB5=M0
this.nPos = nPos; B7NtkMK
oSavedFile.seek(nPos); 5,+\`!g
} .uZ7 -l
ic6L9>[
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public synchronized int write(byte[] b,int nStart,int nLen) [nN7qG
{ OKuD"
int n = -1; HgJb4Fi
try{ 'TN)Lb*
oSavedFile.write(b,nStart,nLen); }|8*sk#[
n = nLen; g=]&A
} g;F"7 ^sg
catch(IOException e) }4jC_ZAupt
{ ty1fcdFZM
e.printStackTrace (); lXrD!1F
} T!q_/[i~7
o|S)C<w
<MD;@_Nz\
return n; ru.5fQU
} 74vmt<Q
NlR"$
2iXoj&3e
} v<rF'D2
L0Vgo<A
W|Ldu;#
/* Iur9I>8h
**SiteInfoBean.java $&-5;4R'0
*/ (;o*eFC F
package NetFox; irxz l3
mE$dO3
}#9(Mul
public class SiteInfoBean { Unl?fXI
='Oj4T
H;vZm[\0N-
private String sSiteURL; //Site's URL QrjDF>
private String sFilePath; //Saved File's Path i3V/`)iz
private String sFileName; //Saved File's Name Hw_o w?
private int nSplitter; //Count of Splited Downloading File ^^LjI
vd~U@-C=R
'%4P;HO
public SiteInfoBean() vgPUIxB@
{//nSplitter的缺省值为5 D(Ix!G/
//default value of nSplitter is 5 !c8L[/L
this("","","",5); #;j9}N
} T`L}[?w
vb=CFV#
VZxTx0: ,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~^o=a?L`<
{ _,;%mK
sSiteURL= sURL; 8Pmwzpk02
sFilePath = sPath; nsJ:Osq|
sFileName = sName; ;x[pM_
this.nSplitter = nSpiltter; ")\aJ8
W}gVIfe
lJ/6-dP
} ~Yk"Hos
+mWjBY
*re 44
public String getSSiteURL() 7c1+t_Ew
{ 8GB]95JWwp
return sSiteURL; ;<6"JP>0
} v4<j
qe?Ggz3p.
mUwUs~PjA
public void setSSiteURL(String value) yjZ2 if
{ EZAm)5:]A
sSiteURL = value; 3z,2utH
} mCk5B*Jy
E2:D(7(;l
qzdaN5
public String getSFilePath() c cr" ep
{ zGs|DB
return sFilePath; /Dd\PjIH{
} pcpxe&S
kyAs'R@z
`!Ln|_,d
public void setSFilePath(String value) Y^eX@dEFR
{ u~Lu<3v
sFilePath = value; &l^n4
} BR3mAF
wixD\t59X
rgR?wXW]jE
public String getSFileName() elKx]%k*)
{ y9 uVCR
return sFileName; Sr7@buF
} m!!;/e?yx
Yk7"XP[Y
7+8bL{
public void setSFileName(String value) vl~%o@*_
{ Ec.)!Hu
sFileName = value; +FBi5h
} M)=|<h"F
)<'yQW=6
h#R&=t1,^
public int getNSplitter() ,)uPGe"y
{ 5rF/323z
return nSplitter; S~&\o\"5
} E!YmcpCl
N[ Q#R~Hn<
.HOY q
public void setNSplitter(int nCount) BD4"pcr
{ /$*; >4=>f
nSplitter = nCount; p2a?9R
} a@k.$
} 2VMX:&3 5J
lxOqs:b
?1DUNZ6
/* wz@/5c/u
**Utility.java +9~ZA3DiP
*/ |0DP} `~
package NetFox; pP oxVvG{
e5qvyUJM
{jUvKB_x
public class Utility { Ps|QW
"o<D;lO
yUj;4vd
public Utility() o3= .T+B
{ '}fel5YV
5Q;dnC
[wIKK/O
} -g$OOJB6
_X?y,#
//线程睡眠 z=%IcSx;
public static void sleep(int nSecond) &08Tns"
{ `x< 0A
try{ (V^QQ !:
Thread.sleep(nSecond); [BE:+ ID3
} )_F(H)*
catch(Exception e) X%35XC.n
{ K9}jR@jy$
e.printStackTrace (); 6i^0T
} ~CulFxu
} (A|B@a!Y>
o:f|zf> i<
//日志 jiOf')d5
public static void log(String sMsg) y,1S&k
{ 6|i`@|#
System.err.println(sMsg); d)9PEtI
} v(k*A:
r5Wkc$
YBeZN98Nt
public static void log(int sMsg) ju r1!rg%
{ V3%Krn1'
System.err.println(sMsg); h#;?9DP
} [I_BCf
} a\Tr!Be,
bL#sn_(m
J;7s/YH^
/* ]~ >@%v&
**TestMethod.java ?<g|.HY/
*/ CARq^xI-
package NetFox; i{4'cdr?
'%3u%;"
?F!W#
public class TestMethod { XZ!cW=bqS
7-(>"75Q|
e|35|I '
public TestMethod() \}n !yYh(
{ ///xx/weblogic60b2_win.exe {W]bU{%.
try{ v5P*<U Ax
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m*OLoZVy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }isCvb
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8x`Kl(
fileFetch.start(); ,d3Q+9/
} \;'_|bu3.
catch(Exception e){e.printStackTrace ();} ;}$Z 80
k`{RXx
.$n$%|"H-
} w 5!ndu
KC#kss
J,.j_ii`!
public static void main(String[] args) WFQ*s4 R(
{ q.U*X5
new TestMethod(); !4i,%Z&6
} b*@&c9I;q
} 0@JilGk1u
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