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)); (WT0j
} }W&hPC
for(int i=0;i<nEndPos.length-1;i++) S.o 9AUv9
{ )@DT^#zR
nEndPos = nStartPos[i+1]; aYQ!`mS::M
} v5"5UPi-
nEndPos[nEndPos.length-1] = nFileLength; g Z3VT{
} [\N,ow,n
} oQJK}9QR
9vc3&r
arf`%9M
//启动子线程 :nki6Rkowt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <p<jXwl
for(int i=0;i<nStartPos.length;i++) xR5jy|2JJ
{ *yAC8\v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rg U$&O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /'U/rjb_h{
nStartPos,nEndPos,i); KA:>7-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >@^z?nb
fileSplitterFetch.start(); c_b^t09
} ?8wFT!J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]/;0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <qH>[\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CL/8p;
nEndPos = " + nFileLength); K~$o2a e
// fileSplitterFetch[nPos.length-1].start(); )fSQTbB;0
-L7Q,"a$
(bH*i\W
//等待子线程结束 [sG=(~BU
//int count = 0; U(5(0r
//是否结束while循环 w?kdM1T
boolean breakWhile = false; Zcd!y9]#
k>#,1GbNZy
,lm.~%}P*
while(!bStop) e#`wshtN:
{ 4)Y=)#=
write_nPos(); W2h^ShG
Utility.sleep(500); P\bW kp0
breakWhile = true; <~# ZtD$G
`+]9+:tS
)_!t9gn*wr
for(int i=0;i<nStartPos.length;i++) fx|$(D@9
{ JBQ,rX_Hw
if(!fileSplitterFetch.bDownOver) R{S{N2+p(
{ M@@"-dy
breakWhile = false; UNLy{0tA
break; 2GECcx53
} . (*V|&n
} K V^`
if(breakWhile) hnS ~r4
break; vW6Pf^yJ
Vf6lu)Zc1
ehj&A+Ip
//count++; "PGEiLY
//if(count>4) ]5D?Sc#-
// siteStop(); DV +DJcF
} #9z\Wblr
u#XNl":x
Vea>T^
System.err.println("文件下载结束！"); A"`62
} h$|K vS
catch(Exception e){e.printStackTrace ();} xin<.)!E
} WQ4:='(
4A0R07"
Z[KXDQn8
//获得文件长度 B&|F9Z6D
public long getFileSize() y|V/xm+Fp
{ )ARfI)<1b
int nFileLength = -1; l i}4d+
try{ 7QL>f5Q
URL url = new URL(siteInfoBean.getSSiteURL()); <jU[&~p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ch,<4E/c[R
httpConnection.setRequestProperty("User-Agent","NetFox"); c:"*MM RC
k!O#6Z
7~TE=t
int responseCode=httpConnection.getResponseCode(); t6_6Bl:
if(responseCode>=400) ?1}1uJMj-
{ j['Z|Am"l
processErrorCode(responseCode); LKY4rY!|@d
return -2; //-2 represent access is error &!JX
} {6'5K U*RH
YcE:KRy
X4*{CM
String sHeader; mzTF2K
> taT;[Oa
Z 2Fm=88
for(int i=1;;i++) 4%2QF F@
{ (.7_`T6QG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <9eQ
//Utility.log(in.readLine()); ("o<D{A
sHeader=httpConnection.getHeaderFieldKey(i); 2S}%r4$n}
if(sHeader!=null) qQ%zSJ?
{ ORlz1&hW
if(sHeader.equals("Content-Length")) HH+NNSRO
{ |{cdXbr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /ow/)\/}
break; 2qKo|'gL`
} sl-LX)*N#
} T=:&W3
else ^sd+s ~xx
break; MzYTEe&-L
} K$(&Qx}
} Z'<=06
catch(IOException e){e.printStackTrace ();} ^*'|(Cv
catch(Exception e){e.printStackTrace ();} j#y_#
z^I"{eT8
~|@aV:k
Utility.log(nFileLength); gt6*x=RCrQ
|ap{+ xh
)ruC_)
return nFileLength; r|cl6s!P
} EaFd1
pmB}a7
ja70w:ja
//保存下载信息（文件指针位置） c`mJrS:
private void write_nPos() b_cnVlN[
{ Y'Sxehx
try{ ?mS798=f
output = new DataOutputStream(new FileOutputStream(tmpFile)); C*ZgjFvB
output.writeInt(nStartPos.length); Xj"/6|X
for(int i=0;i<nStartPos.length;i++) fG;)wQJ
{ `R0>;TdT
// output.writeLong(nPos); L7_Mg{
output.writeLong(fileSplitterFetch.nStartPos); U2/H,D
output.writeLong(fileSplitterFetch.nEndPos); 5.F.mUO
} @no]*?Gpa
output.close(); akgXI^K
} (qlIQC
catch(IOException e){e.printStackTrace ();} Q[scmP^$^
catch(Exception e){e.printStackTrace ();} p=\DZU~1
} 4?g~GI3
z|F>+6l"Y7
4z Af|Je
//读取保存的下载信息（文件指针位置） EonZvT-D=
private void read_nPos() :Y(Yk5
{ NWNH)O@
try{ +cM;d4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); p9XHYf72
int nCount = input.readInt(); (\.[pj%-O
nStartPos = new long[nCount]; lZV]Z3=p'0
nEndPos = new long[nCount]; e<YC=67n)
for(int i=0;i<nStartPos.length;i++) +|r;t
{ lYv :
nStartPos = input.readLong(); fo&q/;l\
nEndPos = input.readLong(); !0c7nzjm
} .\X/o!xC
input.close(); zA9N<0[]o
} 6(B0gBCId
catch(IOException e){e.printStackTrace ();} [=u8$5/a
catch(Exception e){e.printStackTrace ();} Q#urx^aw
} `r'q(M
XJ?|\=]
"v/^nH
private void processErrorCode(int nErrorCode) )FT~gl%
{ 5H:NY|
System.err.println("Error Code : " + nErrorCode); u9"b,].b
} 'IFbD["r
q`E6hm
0aSN8
//停止文件下载 (' /S~
public void siteStop() djqSW9
{ ii2X7Q
bStop = true; a2vUZhkR
for(int i=0;i<nStartPos.length;i++) `hM`bcS
fileSplitterFetch.splitterStop(); ~^$ONmI5
Thn-8DT
^=bJ _'
} 9~ajEs
} *'`ByS
//负责部分文件的抓取 LTS3[=AB
**FileSplitterFetch.java ] $$ciFM
*/ UB&ofO
package NetFox; b.47KJzt
IpGq_TU
fC.-* r
import java.io.*; %Gl,V5z&
import java.net.*; Y<:%_]]
44f8Hc1g
n0 _:!]k^
public class FileSplitterFetch extends Thread { eT[,k[#q
RZjTUMAz4
[WXtR
String sURL; //File URL _D1bR7
long nStartPos; //File Snippet Start Position ,[,+ _A
long nEndPos; //File Snippet End Position M ioS
int nThreadID; //Thread's ID )J<Li!3
boolean bDownOver = false; //Downing is over "'94E,W
boolean bStop = false; //Stop identical }h5pM`|1
FileAccessI fileAccessI = null; //File Access interface .^I,C!O#
u]@``Zb|
)K -@{v^|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /XEcA5C<
{ eg~$WB;1
this.sURL = sURL; (NOAHV0H
this.nStartPos = nStart; 7n,nODbJ
this.nEndPos = nEnd; g}{Rk>k
nThreadID = id; bnUpH3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 GuQ3$B3j
} 7XT2d=)"
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)_NQ*m
public void run() FfI$3:9
{ D*Siy;
while(nStartPos < nEndPos && !bStop) \! Os!s
{ DC]FY|ff
g v&xC 6>
+z+25qWi
try{ <\8dh(>
URL url = new URL(sURL); Yt++?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;EW]R9HCH
httpConnection.setRequestProperty("User-Agent","NetFox"); 93kSBF#
String sProperty = "bytes="+nStartPos+"-"; h#^IT
httpConnection.setRequestProperty("RANGE",sProperty); @NlnZfMu
Utility.log(sProperty); @bmu4!"d
{[hV['Awv
f5 wn`a~h
InputStream input = httpConnection.getInputStream(); hx+a.N
//logResponseHead(httpConnection); kMo;<Z
L'J$jB5cP
mJc'oG-
byte[] b = new byte[1024]; P%xk
int nRead; 1Nx%uz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9j49#wG0"B
{ _T6WA&;8
nStartPos += fileAccessI.write(b,0,nRead); [`=|^2n?
//if(nThreadID == 1) igOjlg_Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L=Dd`
} 5Jp@n .
28d:
.oO_x>
Utility.log("Thread " + nThreadID + " is over!"); =9i:R!,W
bDownOver = true; x/~V ZO
//nPos = fileAccessI.write (b,0,nRead); ]Q-ON&/
} #PVgx9T=_
catch(Exception e){e.printStackTrace ();} ]r$S{<
} Axk p
} "6Nma)8
"@ Zy+zLU
}pu2/44=W
//打印回应的头信息 4Yt:PN2
public void logResponseHead(HttpURLConnection con) F04`MY"
{ j{7_p$JM
for(int i=1;;i++) 1e'-rm F
{ }bIEWho
String header=con.getHeaderFieldKey(i); @0A0\2
if(header!=null) O1JGv8Nr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FGr0W|?v
Utility.log(header+" : "+con.getHeaderField(header)); fH`P8?](x
else "#rlL^9v
break; S!#7]wtbP
} ?%JH4I2
} qK:.j
Um9!<G=;
#`:60#l
public void splitterStop() \'GX^0yK
{ @=K> uyB
bStop = true; xRv1zHZ
} {p9y{$
I=D`:u\H
> 9JzYI^
} _Eq:Qbw#
\$VtwVQ,b
:?RooJ~#
/* 3.Ni%FF`
**FileAccess.java qX0IHe
*//文件访问(定位，写) I:]s/r7
package NetFox; Vd)iv\a
import java.io.*; e&8pTD3
}Da8S|)H
'iXjt MX
public class FileAccessI implements Serializable{ .<u<!fL2
UI<'T3b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hs2f3;)
RandomAccessFile oSavedFile; "2'nLQ""q
long nPos; [uc;M6o}?
j &,vju
'#4ya=Ww
public FileAccessI() throws IOException kR-N9|>i
{ &hB~Z(zS!
this("",0); Z!G;q}zZ!
} GaSk&'n$Y
+TpM7QaL
UB.FX
public FileAccessI(String sName,long nPos) throws IOException h[C!cX
{ h}q+Dw.i
oSavedFile = new RandomAccessFile(sName,"rw"); 6b-d#H/1Y
this.nPos = nPos; Z:,HB]&;9
oSavedFile.seek(nPos); >P>.j+o/
} (4$lB{%
4D$$KSa
C(}9
public synchronized int write(byte[] b,int nStart,int nLen) S?OK@UEJ
{ s]5wzbFO
int n = -1; @K4} cP
try{ J0d +q!
oSavedFile.write(b,nStart,nLen); x\3 ` W
n = nLen; 89`AF1
} _<pG}fmR
catch(IOException e) |ng[s6uf
{ 9C|T/+R
e.printStackTrace (); 9 ?MOeOV8
} WB6g i2
gSZNsiH
>kz5azV0
return n; V/"0'H\"1
} 6xk"bIp
#c+N}eX{
QMy;?,
} *ErTDy(
aZ*b"3
U[U$1LSS
/* +'uF3-+WY
**SiteInfoBean.java 6M"J3\ x
*/ dvyE._/v
package NetFox; L(`^T`
Yah3I@xGy
@o9EX }
public class SiteInfoBean { []3xb`<&
#mk#&i3"k
hB P]^~(
private String sSiteURL; //Site's URL 7R7g$
private String sFilePath; //Saved File's Path qAR~js`5
private String sFileName; //Saved File's Name "Z&qOQg%3
private int nSplitter; //Count of Splited Downloading File ^yy\CtG
O4\GL
|rW}s+Kcr
public SiteInfoBean() "SLN8x49(
{//nSplitter的缺省值为5 w]tv<U={
//default value of nSplitter is 5 ^w8H=UkP!+
this("","","",5); u$t*jw\fHg
} LP@Q8{'
XXuU@G6Z7$
cX7xG U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L.U [eH
{ gWy2$)
sSiteURL= sURL; 87~. |nu
sFilePath = sPath; ukS@8/eJ
sFileName = sName; Bwb3@vNA
this.nSplitter = nSpiltter; %L/Wc,My
ppb]RN|)
kL*Q})
} S;+bQ.
*N\U{)b\
zclt2?
public String getSSiteURL() j[wGR_EE
{ 0u'2f`p*
return sSiteURL; TQE3/IL
} \{{B57/Isq
o6xl,T%
>AN`L`%2
public void setSSiteURL(String value) Ulj2Py}
{ i&mu=J[
sSiteURL = value; Z=825[p
} 5SR29Z[
;]Y.2 J
ZS>}NN
public String getSFilePath() k-e_lSYk&c
{ /Wg$.<!5}
return sFilePath; g@MTKqs
} {n$9o
eW\7X%I
e_k1pox]l
public void setSFilePath(String value) fcnbPO0M
{ a3R#Bg(
sFilePath = value; u;!CQ w/
} Nf-IDK
9y.C])(2
#jA|04w
public String getSFileName() ,GVHwTZ0`
{ RBt"7'
return sFileName; /}#z/m@bN
} S@N&W&W#~
3|9)A+,#
=;dupz\7
public void setSFileName(String value) n U$Lp`
{ aina6@S
sFileName = value; &IXr*I
} sKn>K/4JZ
:E4i@ O7%
e#FaK^V
public int getNSplitter() =]-!
{ c!{.BgGN
return nSplitter; pR`.8MMc8
} F~W*"i+EZ
,dzbI{@6
2#T|+mKxZM
public void setNSplitter(int nCount) r'{pTgm#
{ kRSu6r9
nSplitter = nCount; 'PV,c|f>
} f[%\LHq
} P0' ;65
KkJcHU
p7zHP
/* :Gy .P
**Utility.java ;Jv)J3y
*/ lG fO
package NetFox; I4qzdD
UupQ*,dJ
)c]GgPH
public class Utility { Gp@Y=mU
1MfRFv
| 2p\M?@
public Utility() sl |S9Ix
{ o)"}DeV$&
zr84%_^
KW+^9&lA
} F4kU) i
&rcr])jg[
//线程睡眠 W 86S)+h
public static void sleep(int nSecond) 'qQDM_+
{ 9XobTi3+'
try{ ?D57HCd`n
Thread.sleep(nSecond); \m5:~,p=
} <C# s0UX
catch(Exception e) 1PLKcU
{ I>L lc Y
e.printStackTrace (); jqb,^T|j;m
} Zu&trxnNf[
} xhg{!w
.7~Kfm@2
//日志 U:_T9!fG
public static void log(String sMsg) 9dqD(S#C;"
{ 2=F_<Jh|+
System.err.println(sMsg); I?bL4u$\
} %b@>riR(y
e!eWwC9u
rLh490@
public static void log(int sMsg) ,_\h)R_
{ <0v'IHlZ8
System.err.println(sMsg); .N/4+[2p(
} /~gM,*
} <pK;D
gJvc<]W8!
2kCJqyWy
/* iLv"ZqGrw
**TestMethod.java ^4 es
*/ 5>h2WL
package NetFox; //H+S q66
_or$^.='
X903;&Cim
public class TestMethod { _I5p 7X
.u W_(Rqg
gj6"U{D
public TestMethod() yMX4 f
{ ///xx/weblogic60b2_win.exe %4n=qK9T5
try{ q.Z0Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NmOQ7T
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GbB&kE3KP
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6kIq6rWF9
fileFetch.start(); t MA
} IQ2<Pinv
catch(Exception e){e.printStackTrace ();} ELY$ ]^T
JK,#dA#
RR`?o\
} HV>|f'45
{) Y &Vr5
G=yQYsC$
public static void main(String[] args) ^9cqT2:t
{ P3lNns3
new TestMethod(); 4fP>;9[F
} Fo~C,@/Qt
} 2<u vz<B
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