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)); H:c5 q0O^x
} 9i5?J]o^
for(int i=0;i<nEndPos.length-1;i++) (lM,'
{ F<I*?${[
nEndPos = nStartPos[i+1]; ;98&5X\u<
} [nO3%7t@
nEndPos[nEndPos.length-1] = nFileLength; $K^l=X
} #h[>RtP:
} (I}owr5:
w[-)c6JyE
wN!\$i@E:
//启动子线程 P?h1nxm`'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T/'z,,Y
for(int i=0;i<nStartPos.length;i++) $IE}fgA@5
{ QXZXj#`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jU&m*0nL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f#!+l1GV
nStartPos,nEndPos,i); z^QrIl/<c2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n?@zp<
fileSplitterFetch.start(); TRm#H$
} ZG^<<V$h
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ] ]U)wg
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %b^4XTz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wSjDa.?'
nEndPos = " + nFileLength); 44ty,M3
// fileSplitterFetch[nPos.length-1].start(); _X4Y1zh
Z`tmuu
1jg* DQ7L
//等待子线程结束 4,sE{%vb
//int count = 0; cz9J&Le>
//是否结束while循环 0~ho/_
boolean breakWhile = false; ST?{H SCz
|!PL"]?
I8gNg Z
while(!bStop) '."_TEIF
{ nEsD+}E?
write_nPos(); >.Gmu
Utility.sleep(500); uBRlvNJ
breakWhile = true; _c>ww<*3
B r#{
k77IXT_7u
for(int i=0;i<nStartPos.length;i++) OvX&5Q5
{ {nKw<F2
if(!fileSplitterFetch.bDownOver) :|W=2(>
{ `}?;Ow&2CY
breakWhile = false; QOXo(S
break; 3lp'U&3`5
} Lm4`O%
} J>A9]%M
if(breakWhile) 01?+j%k=m/
break; 5C!zEI)
}%u#TwZ
D -tRy~}
//count++; K+}0:W=P
//if(count>4) V~dhTdQ5}
// siteStop(); [q?RJmB]
} c*ueI5i
* 1;4&/93o
^`kwSC
System.err.println("文件下载结束！"); b-<0\@`Z#
} v?VDASR2`
catch(Exception e){e.printStackTrace ();} >Q/;0>V
} 1#=9DD$4
h <4`|Bg+
/i,n75/y?
//获得文件长度 Lu}jk W*
public long getFileSize() %nZ:)J>kz
{ 9`*ST(0/
int nFileLength = -1; `D77CC]vU
try{ 5pJe`}O4
URL url = new URL(siteInfoBean.getSSiteURL()); "TA0--6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LaQ7A,]
httpConnection.setRequestProperty("User-Agent","NetFox"); h+W$\T)
'f6H#V*C
@[g7\d
int responseCode=httpConnection.getResponseCode(); 3jAr"xc
if(responseCode>=400) O t)}:oG
{ &4:R(]|
processErrorCode(responseCode); M(a%Qk?]/
return -2; //-2 represent access is error Vc9rc}
} lOt7ij(,L
e-rlk5k%f
MZV$YD^S
String sHeader; x4* bhiu
+.!D>U$)}
a$=~1@
for(int i=1;;i++) @s1T|}AJ
{ 6M >@DRZ'|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =^KgNQ
//Utility.log(in.readLine()); |6Q5bV
sHeader=httpConnection.getHeaderFieldKey(i); 8* A%k1+
if(sHeader!=null) v@=qVwX
{ @-sWXz*W
if(sHeader.equals("Content-Length")) ,>-jZtm
{ P PJ^;s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p^8a<e?f~f
break; xxur4@p!
} 8oJl ]
} [#Qf#T%5h
else ;U=b6xE
break; G[>NP#P
} bG]0|
} 1d< b\P0
catch(IOException e){e.printStackTrace ();} %6 *c40
catch(Exception e){e.printStackTrace ();} Z<;W*6J
N (4H}2
~2Wus8X-
Utility.log(nFileLength); #Nh'1@@
EnWv9I<
)95k3xo
return nFileLength; /wLBmh1"
} qSNCBn '
rQ.zqr
o-=|}u]mz
//保存下载信息（文件指针位置） f8;?WSGyD2
private void write_nPos() }<^mUG
{ OInl?_,,T#
try{ N-K/jY
output = new DataOutputStream(new FileOutputStream(tmpFile)); !'N@ZZ
output.writeInt(nStartPos.length); m54>}
for(int i=0;i<nStartPos.length;i++) #4Z e2T|
{ 1b~21n
// output.writeLong(nPos); #+ch
output.writeLong(fileSplitterFetch.nStartPos); #NFB=oJI
output.writeLong(fileSplitterFetch.nEndPos); 94w)Yln
} Q$U5[TZm
output.close(); (X "J)xaQ
} \ivxi<SR
catch(IOException e){e.printStackTrace ();} 'V?FeWp
catch(Exception e){e.printStackTrace ();} 0OM^,5%8
} i M !`4
#uU(G\^T
1b3 a(^^E
//读取保存的下载信息（文件指针位置） DKjiooD
private void read_nPos() .Exvuo`F
{ f]i"tqoI
try{ =6~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ?"Ez
int nCount = input.readInt(); ;<M}ZL@m
nStartPos = new long[nCount]; Ikdj?"+O
nEndPos = new long[nCount]; Z+v,o1
for(int i=0;i<nStartPos.length;i++) `^[k8Z(
{ A;L ]=J
nStartPos = input.readLong(); N~,Ipf
nEndPos = input.readLong(); O]tR~a
} %j\&}>P4$
input.close(); ui>jJ(
} Kzrd<h]`)
catch(IOException e){e.printStackTrace ();} uP* kvi:e
catch(Exception e){e.printStackTrace ();} RxqNgun@
} )c4tGT<
YD[HBF)~j
5[4wN( )
private void processErrorCode(int nErrorCode) qHub+"2
{ _|u}^MLO
System.err.println("Error Code : " + nErrorCode); AJ}FHym_ZQ
} v/ N[)<
Ro]Z9C>1o
`-{l$Hn9|~
//停止文件下载 *,z/q6
public void siteStop() s>/Xb2\
{ {g.YGO
bStop = true; YIRe__7-NU
for(int i=0;i<nStartPos.length;i++) (c[u_~ ;
fileSplitterFetch.splitterStop(); TX=894{nGh
_p6r5Y
5.\p]>|G1
} mS'Ad<
} ;d}>8w&tfy
//负责部分文件的抓取 Z4i))%or
**FileSplitterFetch.java x:Q\pZ
*/ !\7M7
package NetFox; ~6;I"0b5
3`&FXgo
*>a=ku:?
import java.io.*; WOn<;'}M&
import java.net.*; bN/8~!
R>0[w$
SEM?vQ 0"}
public class FileSplitterFetch extends Thread { HTYyX(ya
X|a{Z*y;r*
%e]G]B%
String sURL; //File URL 7dY_b
long nStartPos; //File Snippet Start Position 6B8!}6Ojc
long nEndPos; //File Snippet End Position .T3N"}7[
int nThreadID; //Thread's ID )vO"S
boolean bDownOver = false; //Downing is over 5@xR`g-
boolean bStop = false; //Stop identical F\r"Y)|b=
FileAccessI fileAccessI = null; //File Access interface "d)YqQ
#ELeW3 S}
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B2kZ_4rB
{ fx|d"VF[
this.sURL = sURL; t}k:wzZ@
this.nStartPos = nStart; b@CjnAZ
this.nEndPos = nEnd; 6]iU-k0b
nThreadID = id; W+a/>U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 #HgNwM
} "Vq= Ph
J>v[5FX+
skl3/!
public void run() vSHPN|*
{ d3q%[[@
while(nStartPos < nEndPos && !bStop) xmnBG4,f
{ <<01@Q <
znE1t%V
dXxf{|gk>
try{ 5@5*}[M
URL url = new URL(sURL); >h8m)Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c~tl0XU1
httpConnection.setRequestProperty("User-Agent","NetFox"); ZRf9'UwS
String sProperty = "bytes="+nStartPos+"-"; |Lg2;P7\
httpConnection.setRequestProperty("RANGE",sProperty); &lLk[/b
Utility.log(sProperty); ,;t:x|{%
_]*YSeh=
JxinfWk
InputStream input = httpConnection.getInputStream(); {?:]'c
//logResponseHead(httpConnection); ;\w3IAa|V
~qqxHymc
<<LLEdB
byte[] b = new byte[1024]; bRu9*4t
int nRead; kqKT>xo4EZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5)< Y3nU~
{ 48wt
nStartPos += fileAccessI.write(b,0,nRead); %JBLp xnq
//if(nThreadID == 1) ta{24{?M\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eOb--@~8
} rY(7IX
~T;:Tg*
KD A8x W
Utility.log("Thread " + nThreadID + " is over!"); M ]047W
bDownOver = true; `F/R:!v
//nPos = fileAccessI.write (b,0,nRead); E "=4(
} +#,J`fV%
catch(Exception e){e.printStackTrace ();} Z5TA4Q+Q
} Rf0so
} we_CF*zj
eHvUgDt
l8?C[,K%
//打印回应的头信息 :jv(-RTI
public void logResponseHead(HttpURLConnection con) L'Cd`.yVO
{ A4,%l\di<
for(int i=1;;i++) BlpyE[h T
{ JE}VRMNr
String header=con.getHeaderFieldKey(i); 5,,'hAq_
if(header!=null) !@lx|=#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a!bW^?PcK
Utility.log(header+" : "+con.getHeaderField(header)); U Y*`R
else bXJ(QXHd%
break; d_we?DZ|
} a_!H_J
} N & b3cV
iT&4;W=72~
rSv,;v
public void splitterStop() *DIY;)K
{ *=oO3c0|b,
bStop = true; +-qk\sQ
} ez32k[eV!
,oH\rrglf
$B?8\>_?
} <eEIR
B](R(x>L
33<{1Y[Q6E
/* 3!F^vZ.
**FileAccess.java G~y:ZEnN[
*//文件访问(定位，写) OB9E30
package NetFox; &S xF"pYV
import java.io.*; 8SRUqe[H]
q`mxN!1[
sDBSc:5+e
public class FileAccessI implements Serializable{ ~8&->?{
! 7V>gWhR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H_@6!R2
RandomAccessFile oSavedFile; DNZ,rL:h
long nPos; b4wT3
445JOP
M-].l3
public FileAccessI() throws IOException :q3w;B~
{ 3:Nc`tM_
this("",0); 3PvxU|*F
} U;iCH
Gjeb)Y6N
g"" 1\rc=
public FileAccessI(String sName,long nPos) throws IOException MJX4;nbl
{ ??aO3Vm{
oSavedFile = new RandomAccessFile(sName,"rw"); QlvP[Jtr
this.nPos = nPos; I(7GVYM
oSavedFile.seek(nPos); Pqx?0f)
} mfg>69,w
fsPsP`|
6p }a!
public synchronized int write(byte[] b,int nStart,int nLen) ShL!7y*rT{
{ F(.`@OO
int n = -1; oUsfO-dET^
try{ hN K wQ
oSavedFile.write(b,nStart,nLen); 43h06X`
n = nLen; HqsqUS3[
} [2xu`HT02
catch(IOException e) Y[)mHs2
{ nHeJ20
e.printStackTrace (); xO:h[
} u(3 uZ:
XK\nOHLS
!pU^?Hy=
return n; l[_antokn
} >Z*b0j
ZDaHR-%Y
d)U(XiK'
} | eCVq(R
s%y<FXUj
j~Fd8]@
/* [Y!HQ9^LEp
**SiteInfoBean.java XM5)|D
*/ ':}9>B3 S
package NetFox; h/A\QW8Sd
;]xc}4@=mg
_)<5c!
public class SiteInfoBean { uQbag]&j
;;i419
SVwxK/Fci
private String sSiteURL; //Site's URL DM v;\E~D
private String sFilePath; //Saved File's Path zmZU"eWp)
private String sFileName; //Saved File's Name p:b{>lM
private int nSplitter; //Count of Splited Downloading File qF^P\cD
HOu$14g
k@%5P-e}
public SiteInfoBean() $-]G6r
{//nSplitter的缺省值为5 .9Oj+:n
//default value of nSplitter is 5 !21G$[H
this("","","",5); UVLS?1ra
} CLZj=J2
>0:3CpO*
O[$X36z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?glx8@
{ N:Q.6_%^
sSiteURL= sURL; 2{WZ?H93a
sFilePath = sPath; vv)w@A:Vn)
sFileName = sName; y|BHSc3
this.nSplitter = nSpiltter; uPcx6X3]
q]f7D\ M
i@6g9\x+
} |FT.x9e-
m;"[b (u
~t2"L|i
public String getSSiteURL() U) xeta+
{ %!-t7K^mFq
return sSiteURL; *`qI<]!
} w(_:+-rqQ<
L-U4 8 i
p`&{NR3+
public void setSSiteURL(String value) s\3]0n9
{ c8]%,26.
sSiteURL = value; h*KDZ+{)
} A #SO}c
c)Ef]E\
9wc\~5{li
public String getSFilePath() =>>Dnp
{ K)l*$h&-
return sFilePath; D`Vb3aNB=L
} #p;<X|Hc}8
2=fLb7
LjGLi>kI~
public void setSFilePath(String value) GCQOjqiR
{ cEp/qzAiD%
sFilePath = value; w=-{njMz6&
} OAo03KW
n}b/9
\Qv:7;?
public String getSFileName() Vm@VhCsp
{ X`v6gv5qj
return sFileName; (/&ht-~EL
} Q ijO%)
Qu<HeSA_
8Rw:SU9H?T
public void setSFileName(String value) #,lbM%a
{ \QSD*
sFileName = value; ~ cu+QR)
} c uAp,!
/^{Q(R(X<
GRL42xp'*D
public int getNSplitter() /;Cx|\
{ xPT$d,~"
return nSplitter; cbou1Ei
} uVZm9Sp
"/^kFsvp
s#0m
public void setNSplitter(int nCount) j;Lp@~M
{ biV|W@JM
nSplitter = nCount; 26zif
} uGlz|C
} M>RLS/r>d
NJ}xqg
uY3$nlhP6
/* 1Ogtzf
**Utility.java ByWad@-6i
*/ tx3p, X
package NetFox; ;F,6]LH!
-jTK3&5
_mQ~[}y+?
public class Utility { k ;vOPcw
[daR)C
LWM& k#i
public Utility() :SF8t`4`
{ R*dXbI&,e
Ax!@vL&@
TxkvHiq2
} Bt\V1)
I.6#>=
//线程睡眠 =`(\]t"I
public static void sleep(int nSecond) aQ 6T2bQ
{ hA~5,K0b
try{ h*[sV
Thread.sleep(nSecond); W89J]#v)k
} .d)H2X
catch(Exception e) wE <PXBl\b
{ M@.?l=1X
e.printStackTrace (); qP%[nY
} T5-'|+
} |>I4(''}
%s%e5hU
//日志 QmPHf*w[
public static void log(String sMsg) TlQ5'0&I
{ Tkf4`Gxd
System.err.println(sMsg); %%O_:@9x,
} c$hoqi |tD
7,9zj1<
c%n%,R>
public static void log(int sMsg) #0qMYe>Y
{ exm*p/
System.err.println(sMsg); C\[g>_J
} Q},uM_"+
} fV/
LTD;
<8Q?kj
/* !%C&hH\
**TestMethod.java *UG=dl#F#
*/ P}p6{
package NetFox; oP<E)
eY$Q}BcW
+7)/SQM5
public class TestMethod { ^yF2xJ)9-
f=MR.\
/0F <GBQ"v
public TestMethod() vi.q]$ohbV
{ ///xx/weblogic60b2_win.exe b(g?X (&
try{ OEN'c0;5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Zf`ddT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (e{pAm
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0.t1p(x;
fileFetch.start(); W&k2z,|
} TH}+'m
catch(Exception e){e.printStackTrace ();} O~g0R6M6e
&_c5C
{7q +3f <
} myY@Wp
{5:V hW}
cm7>%g(oQo
public static void main(String[] args) B7qiCX}pD
{ lT]dj9l
new TestMethod(); Ed~2Qr\65
} D8_-Dvp7H
} EabZ7zFoN
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