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)); v'W{+>.
} uuC ["Z
for(int i=0;i<nEndPos.length-1;i++) X-c|jn7
{ vd%g'fTy9
nEndPos = nStartPos[i+1]; ^65I,Z"
} :ky`)F`
nEndPos[nEndPos.length-1] = nFileLength; xb,XI/
} 6 c_#"4
} vMTf^V
s1:Wrz?4
DB/~Z
//启动子线程 hNN>Pd~;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; z'YWomfZm
for(int i=0;i<nStartPos.length;i++) !5`MiH
{ 0!hr9Y]Lx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x-BU$bx5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5Gz!Bf@!!
nStartPos,nEndPos,i); im<bo Mv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4t, 2H"M
fileSplitterFetch.start(); 1Bj.MQ^
} $.PRav
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !eW1d0n'+f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K./qu^+k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yw^Pok5.
nEndPos = " + nFileLength); uo#1^`P
// fileSplitterFetch[nPos.length-1].start(); ${f<}
daE.y_9y
%K6veB{M
//等待子线程结束 7he73
//int count = 0; 6"&cQ>$xh
//是否结束while循环 r48|C{je-
boolean breakWhile = false; /ZvP.VW&
EXDDUqZ5\
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while(!bStop) qSY\a\.<
{ "#1\uoH
write_nPos(); Rb6BY-/J
Utility.sleep(500); r,6~%T0
breakWhile = true; )w7vE\n3
IW~R{ ]6
=:H-9
for(int i=0;i<nStartPos.length;i++) =U]9>
{ %_(vSpk
if(!fileSplitterFetch.bDownOver) W A/dt2D|
{ 3=O [Q:8
breakWhile = false; c!EA>:;(<
break; sxNf"C=-.
} 3#7V1
} 1j?P$%p
if(breakWhile) &Hoc`u
break; &*`dRIQ]
@{/)k%U
y``\^F
//count++; @6;OF5VsQ
//if(count>4) GcV/_Y
// siteStop(); cY?|RXNmZ
} fn}E1w
cMT7Bd
K~L&Z?~|E
System.err.println("文件下载结束！"); I}`pY3
} f_~T
catch(Exception e){e.printStackTrace ();} .p[uIRd`
} +~8Lc'0aA
h FU8iB`Q
#u&fUxM:AS
//获得文件长度 R"cQyG4
public long getFileSize() be+-p
{ cv'8_3
int nFileLength = -1; 2yfU]`qN
try{ /~,*DH$)
URL url = new URL(siteInfoBean.getSSiteURL()); i}m'#b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P(aBJ*((~
httpConnection.setRequestProperty("User-Agent","NetFox"); !tq]kKJ3:
fFJ7Y+^
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int responseCode=httpConnection.getResponseCode(); 7KgaXi3r
if(responseCode>=400) xlv(PVdn
{ ~XR('}5D
processErrorCode(responseCode); +`d92Tz
return -2; //-2 represent access is error }a"=K%b<\
} VY6G{f
#9GfMxH
-Q? i16pM
String sHeader; d+DO}=]
, z\Qd07u
bB<S4@jF8z
for(int i=1;;i++) AXbb-GK
{ J!Z6$VERy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kFjv'[Y1N
//Utility.log(in.readLine()); ,!Wo6{'
sHeader=httpConnection.getHeaderFieldKey(i); -6)nQNj|
if(sHeader!=null) (wu'FFJp#
{ c/Pql!h+
if(sHeader.equals("Content-Length")) lWRl
{ 3EYEd39E
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); SPqJ [F
break; b ri[&=
} > TYDkEs0
} L} R"1O
else P5my]4|x
break; i ;B^I8
} _|e&zr
} b36{vcs~
catch(IOException e){e.printStackTrace ();} (Z<@dkO?)
catch(Exception e){e.printStackTrace ();} !SuflGx,q
:2j`NyLI.
g;Ugr8
Utility.log(nFileLength); M4Cb(QAVP
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GP+=b:C{E
return nFileLength; Sfe[z=7S
} 3?D, Wu
'/`O*KD]
2Pb+/1*ix
//保存下载信息（文件指针位置） A\?t^T
private void write_nPos() 2#NnA3l]x%
{ zWo
try{ +C\79,r
output = new DataOutputStream(new FileOutputStream(tmpFile)); * 1}dk`-
output.writeInt(nStartPos.length); NrS+N;i
for(int i=0;i<nStartPos.length;i++) \JPMGcL
{ q25p3
// output.writeLong(nPos); YnnK]N;\x
output.writeLong(fileSplitterFetch.nStartPos); 25Ee+&&%
output.writeLong(fileSplitterFetch.nEndPos); c) Eu(j\#
} MR|A_e^x
output.close(); y9mV6.r
} <k[_AlCmsg
catch(IOException e){e.printStackTrace ();} yl?LXc[)
catch(Exception e){e.printStackTrace ();} z:S:[X0
} $cn8]*Z=
;|K }
SN)Czi#7
//读取保存的下载信息（文件指针位置） ^/Hf$tYI!`
private void read_nPos() >!Gq[i0
{ .oM- A\!
try{ V=fu[#<@Ig
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (,sz.
int nCount = input.readInt(); BHp>(7,
nStartPos = new long[nCount]; Z:^<NdKe
nEndPos = new long[nCount]; 1/1oT
for(int i=0;i<nStartPos.length;i++) lI46 f
{ \>4>sCC
nStartPos = input.readLong(); d_(;sW"I
nEndPos = input.readLong(); =oXlJ[)h
} c611&
input.close(); `6-flc0r
} /Q W^v;^
catch(IOException e){e.printStackTrace ();} 5M>p%/
catch(Exception e){e.printStackTrace ();} 1\Bh-tzB
} B t3++ Mj
OLF6["0Rn
~tTa[_a!
private void processErrorCode(int nErrorCode) A'![*O
{ .+Q1h61$T
System.err.println("Error Code : " + nErrorCode); _[8JSw7
} k~;~i)Eg
A##Q>|>)
~BTm6*'h
//停止文件下载 nzxHd7NIZ
public void siteStop() vR#MUKfh
{ K~]Xx~F
bStop = true; ?r]0%W^
for(int i=0;i<nStartPos.length;i++) V@LBy1z
fileSplitterFetch.splitterStop(); P{s1NorKDh
Yrf?|,
S\ZCZ0
} r.@UH-2c
} VwBw!,%Ab
//负责部分文件的抓取 >yenuqIKQv
**FileSplitterFetch.java 6_8yQ
*/ eJ[+3Wh
package NetFox; /QlzWson
ZHwN3
*XDe:A
import java.io.*; \p\p~FVS
import java.net.*; R/B/|x
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cWQ &zc
public class FileSplitterFetch extends Thread { x`p908S^
]LCL?zAzH!
@VND}{j
String sURL; //File URL t ~]' {[F
long nStartPos; //File Snippet Start Position PHez5}T
long nEndPos; //File Snippet End Position =%}(Dvjv
int nThreadID; //Thread's ID \/wk!mWV@
boolean bDownOver = false; //Downing is over B'B0e`
boolean bStop = false; //Stop identical KKg\n^
FileAccessI fileAccessI = null; //File Access interface ,o `tRh<
, P1m#
fP;I{AiN~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SoCN.J30
{ MD0d
this.sURL = sURL; E-9>lb
this.nStartPos = nStart; RXWdqaENx
this.nEndPos = nEnd; RY,L'GtO
nThreadID = id; q`|E9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pP\^bjI
} sBxCi~
925T#%y
{j[*:l0Ui
public void run() "|WKK}
{ *rm[\
while(nStartPos < nEndPos && !bStop) hR>`I0|p&
{ ZTGsZ}{5
+miL naO~L
s,laJf
try{ >G0ihhVt
URL url = new URL(sURL); MzW!iG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EL *l5!Iu
httpConnection.setRequestProperty("User-Agent","NetFox"); hg^klQD
String sProperty = "bytes="+nStartPos+"-"; C0>)WVCK
httpConnection.setRequestProperty("RANGE",sProperty); X-"0Zc
Utility.log(sProperty); 3\B~`=*q/
`Z`o[]%
M7gqoJM'Q
InputStream input = httpConnection.getInputStream(); AUU(fy#<
//logResponseHead(httpConnection); ZI!;~q
' b,zE[Q
9\r5&#<(I
byte[] b = new byte[1024]; bOlb
int nRead; x}7Xd P.2$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) rqM_#[Y?
{ @^Kw\s
nStartPos += fileAccessI.write(b,0,nRead); p!(]`N
//if(nThreadID == 1) m`,h nDp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (jh0cy}|]
} ;Ac!"_N?7
"L)?dlb6T
fqm6Pd{:(
Utility.log("Thread " + nThreadID + " is over!"); HxShNU
bDownOver = true; J\ ?
//nPos = fileAccessI.write (b,0,nRead); a3_pF~Qx
} e5sQl1
catch(Exception e){e.printStackTrace ();} 04E#d.o'
} IkLcL8P^
} gM v0[~;u
_4t
n6GB2<y
//打印回应的头信息 f:A1j\A?
public void logResponseHead(HttpURLConnection con) W'C~{}c=
{ *i7|~q/u
for(int i=1;;i++) (Mt-2+"+
{ n\4sNoFI
String header=con.getHeaderFieldKey(i); L q;=UE
if(header!=null) #Ic-?2Gn4<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hzy#%FaB
Utility.log(header+" : "+con.getHeaderField(header)); ,-Yl%R.W=
else 0a's[>-'A
break; h\OMWJ~
} Ivc/g,
} ~$ "P\iJ
#6Fc-ysk:
O>2i)M-h9x
public void splitterStop() e:WKb9nT
{ Md1ePp]
bStop = true; :.fm LL
} 8}!WJ2[R
UJQGwTA W
'WJ3q|o/
} ;[[oZ
-Y/c]g
1ihdH1rg[
/* T [2l32
**FileAccess.java sb*)K,U
*//文件访问(定位，写) 2GBE=T
package NetFox; &BJ"T
import java.io.*; :^992]EBEj
05o 1
/~;om\7r
public class FileAccessI implements Serializable{ X< p KAO\
@ZGD'+zd?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5X,|Pn
RandomAccessFile oSavedFile; 7y'2
long nPos; _T.k/a
OS$^>1f"
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public FileAccessI() throws IOException 2"!s8x1$
{ =^`?O* /;
this("",0); Y4I;-&d's
} |'N)HH>;
*t,1(Gw|7q
XMw*4j2E
public FileAccessI(String sName,long nPos) throws IOException 'yR)z\)
{ R*r;`x
oSavedFile = new RandomAccessFile(sName,"rw"); \d}>@@U&
this.nPos = nPos; YGf<!
oSavedFile.seek(nPos); "TP^:Ln
} .*Ylj2nM
0;2"X[e
:SvgXMY@
public synchronized int write(byte[] b,int nStart,int nLen) |58xR.S'g
{ rki0!P`
int n = -1; EN;s 8sC!
try{ |!E: [UH
oSavedFile.write(b,nStart,nLen); 'Uu!K!
n = nLen; 1j?+rs+o-
} XsbYWJdds
catch(IOException e) 9vI<\ Xa
{ jcL%_of
e.printStackTrace (); z^^)n
} Yh2[ nF_
X)b@ia'"Wp
Z|$M 9E
return n; 2rPmu
} _kXq0~
}WDzzjDR+
;7E c'nC4
} Wmc@: (n
3>QkO.b
bYAtUEv
/* dTZ$92<
**SiteInfoBean.java #gsJ tT9
*/ '8w>=9Xl
package NetFox; D$Eq~VQ
*WaqNMD[%
{;vLM* '
public class SiteInfoBean { 5yk#(i7C
M>[e1y>7
'e/wjV
private String sSiteURL; //Site's URL U*4r<y9R
private String sFilePath; //Saved File's Path sOVU>tb\'
private String sFileName; //Saved File's Name 7zq@T]
private int nSplitter; //Count of Splited Downloading File );;UA6CD
&&g02>gE
/V GI@"^v
public SiteInfoBean() !|Wf mU
{//nSplitter的缺省值为5 pZz\o
//default value of nSplitter is 5 &EmG\vfE
this("","","",5); \{ve6`7Rn
} % :h%i|
VwOcWKD
Q_>W!)p Gz
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q[{RNab
{ jn(%v]
sSiteURL= sURL; $*;`$5.x^
sFilePath = sPath; _&%FGcAS
sFileName = sName; )2a)$qx;
this.nSplitter = nSpiltter; X|-[i hp;
;y_]w6|n
E!_3?:[S_
} 4Cv*zn
,x$^^
XBoq/kbw!
public String getSSiteURL() 2VzYP~Jg
{ "}V_.I*+
return sSiteURL; Xv3pKf-K
} .5uqc.i"f
"([/G?QAG
Lw2VdFi>E&
public void setSSiteURL(String value) T<-_#}.Hn
{ 4jt(tZS
sSiteURL = value; P?S]Q19Q4
} -We9 FO~
NBHpM}1xtU
qV6WT&)T
public String getSFilePath() ]f0OmUHR5i
{ sM+~x<}0
return sFilePath; Ptf(p`
} #*:^\z_Jd
kg 8Dn
_OC@J*4.
public void setSFilePath(String value) M~N/er
{ `CI_zc=jx
sFilePath = value; X =%8*_
} fbU3-L?
$rI 1|;^
*mVg_Kl
public String getSFileName() UKQ"sC
{ M(zZ8#
return sFileName; xEk8oc
} S>r",S
+D:8r|evH
Lm=;Y6'`N
public void setSFileName(String value) HC/z3b;
{ bi^?SH\
sFileName = value; HA*L*:0
} r34MDUZdI
L-!1ybB^
"X8jpg
public int getNSplitter() F,{mF2U*$
{ !TJ,:c]4{!
return nSplitter; CF2Bd:mfZ
} kJp~'\b
2Jio_Hk
80wzn,o S
public void setNSplitter(int nCount) ,_fz)@)
{ u}gavG l
nSplitter = nCount; 6oNcj_?7?q
} NOuG#P
} > 'hM"4f
hU8Y&R)=9
52dD(
/* J+J,W5t^
**Utility.java +ti ?7|bK<
*/ Zn'tNt/
package NetFox; N);w~)MYh
B-R#?Xn:!I
)&Oc7\J,
public class Utility { M .b8 -`V
YR9fw
a+E&{pV
public Utility() 4=xi)qF/@
{ -f)fiQ-<
>H!Mx_fDL
6:]N%
} r8J7zTD&
"y,YC M`
//线程睡眠 lUm(iYv;H
public static void sleep(int nSecond) o)AwM"
{ ViPC Yt`of
try{ [|DKBJ
Thread.sleep(nSecond); En?V\|,
} :TH cI;PG8
catch(Exception e) ?Gki0^~J
{ bf"'xn9
e.printStackTrace (); hj [77EEz
} ZgP%sF
} <+i(CGw
I6W`yh`I)
//日志 amu;grH
public static void log(String sMsg) V&M*,#(?
{ d;Vy59}eY
System.err.println(sMsg); 3@>F-N
} nqcq3o*B
cz>,sz~i
G*fo9eu5$
public static void log(int sMsg) Je1d|1!3
{ "is(
System.err.println(sMsg); q@|+`>h
} Km` SR^&\
} nT6y6F_e
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/* 'o>)E>
**TestMethod.java eqo0{e
*/ Dqx#i-L23
package NetFox; ]pax,|+$C
w,LtQhQ
m&UP@hUV-
public class TestMethod { xM*_1+<dT$
eUyF<j
PsY![CPrW
public TestMethod() 2Je$SE8
{ ///xx/weblogic60b2_win.exe 9%!h/m>rW
try{ U v2.Jo/Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;H_/o+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -aoYoJ '
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^X=Q{nB
fileFetch.start(); :t}\%%EbmE
} 4CNrIF@
catch(Exception e){e.printStackTrace ();} P6:9o}K6
f98,2I(>`+
;O"?6d0
} sVLvnX,
qpjY &3SI
Ot=jwvw
public static void main(String[] args) 067c/c
{ d+9V% T
new TestMethod(); +#}GmUwPG$
} = tv70d'
} ^|Ap_!t$;
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