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)); pA9^-:\*
} io^^f|
for(int i=0;i<nEndPos.length-1;i++) Ul7)CT2:
{ 7a 4G:
nEndPos = nStartPos[i+1]; Kf D8S
} z 7OTL<h
nEndPos[nEndPos.length-1] = nFileLength; jI!}}K)d
} wN8-Me
} TG'_1m*$
^B~z .F i
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//启动子线程 jV`xRjh
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; HYf&0LT<11
for(int i=0;i<nStartPos.length;i++) r`}')2
{ %JmSCjt`G
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;muxIr`?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hSE\RX 9
nStartPos,nEndPos,i); 1foy.3g-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .<j\"X(
fileSplitterFetch.start(); x\!Q[
} b&X- &F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >8+:{NW
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }2;~':Mklz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J@w Q3#5a
nEndPos = " + nFileLength); eS9uKb5n(
// fileSplitterFetch[nPos.length-1].start(); ` WIv|S
}8Tr M0q8
]Ec\!,54u
//等待子线程结束 wB}s>o\
//int count = 0; ]Sg4>tp
//是否结束while循环 8C3oj
boolean breakWhile = false; +gh6eY8
chW 1UE
y`!~JL*
while(!bStop) }stc]L{79
{ ~]P_Yd-|
write_nPos(); =B_vQJF2
Utility.sleep(500); )*ocX)AE
breakWhile = true; .^0@^%Wi
Ew1> m'
<m:8%]%M6
for(int i=0;i<nStartPos.length;i++) ?bu-6pkx]
{ |GJSAs"L@
if(!fileSplitterFetch.bDownOver) VJ;4~WgBz
{ ^w'y>uFM
breakWhile = false; f"j~{b7
break; :r*skV|
} FjD`bhw-
} 1TeYA6 t
if(breakWhile) zLdi
break; EEmYfP[3
Qvt
1:5jUUL8
//count++; =NxT9$V
//if(count>4) daS l.:1
// siteStop(); (;-< @~2
} v1wMXOR
[h20y
T 2Uu/^
System.err.println("文件下载结束！"); [k qx%4q)
} p2Yc:9r9+A
catch(Exception e){e.printStackTrace ();} _?Q0yVH;,
} {akSK
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S[g{ )p)
//获得文件长度 hfzmv~*
public long getFileSize() |Et8FR3[m
{ \/E+nn\)
int nFileLength = -1; M'gw-^(
try{ A#/O~-O^
URL url = new URL(siteInfoBean.getSSiteURL()); );-?~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AG?cI@',
httpConnection.setRequestProperty("User-Agent","NetFox"); S+aXlb
;jC}.] _)w
4O}ZnE1[
int responseCode=httpConnection.getResponseCode(); t.0F
if(responseCode>=400) ^lADq']
{ [Aqy%mbG
processErrorCode(responseCode); :Y/>] tS4
return -2; //-2 represent access is error VHwAO:+-
} _`'VOY`o
Wx~N1+
/{h@A~<96
String sHeader; /1A3 Sw
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-2Bkun4Pt
for(int i=1;;i++) #6w\r&R6
{ %NH#8#';2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xLID@9Hbu
//Utility.log(in.readLine()); `xb\)
sHeader=httpConnection.getHeaderFieldKey(i); PHZ+u@AA6@
if(sHeader!=null) IY$v%%2WZ
{ U7GgGMw
if(sHeader.equals("Content-Length")) !h\>[O
{ $Sz@u"ig%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M1UabqQ
break; O{YT6&.S0
} # !:u*1
} "gaurr3
else 6MsVV_/
break; q.xt%`@aA
} !'yCB9]O
} +MHsdeGU1W
catch(IOException e){e.printStackTrace ();} t(d$v_*y51
catch(Exception e){e.printStackTrace ();} g7Xjo )
DcjF$E
|AgdD
Utility.log(nFileLength); j%_{tB
?%)G%2
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return nFileLength; `;X~$uS
} _SVIY@K|/
O$ p
'aj97b;lpG
//保存下载信息（文件指针位置） mI$<+S1!
private void write_nPos() "#<P--E9
{ #RfNk;kaA
try{ cJp:0'd
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2kG(\+\
output.writeInt(nStartPos.length); '+%<\.$
for(int i=0;i<nStartPos.length;i++) G&2UXr3
{ vIMLUL0
// output.writeLong(nPos); |->P|1 P
output.writeLong(fileSplitterFetch.nStartPos); `Mg&s*
output.writeLong(fileSplitterFetch.nEndPos); 8:D|[u;iG
} /"Z6\T9
output.close(); /y2)<{{I
} p'@|Oq&
catch(IOException e){e.printStackTrace ();} Y! 8 I
catch(Exception e){e.printStackTrace ();} 3izGMH_`
} sN"JVJXi
Ah_,5Z@&R
9i^dQV.U=
//读取保存的下载信息（文件指针位置） v|]1x2191
private void read_nPos() 7dg2-4
{ [unK5l4_!
try{ QGC%, F"+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Un~ }M/
int nCount = input.readInt(); >^fpQG
nStartPos = new long[nCount]; `jI$>{oa
nEndPos = new long[nCount]; +mgm39
for(int i=0;i<nStartPos.length;i++) Es7+bFvsE8
{ f!H~BMA+a
nStartPos = input.readLong(); w!GPPW(
nEndPos = input.readLong(); )qbjX{GZ7
} -gq,^j5,
input.close(); |(evDS5
} F]fBFDk
catch(IOException e){e.printStackTrace ();} .m;5s45O{
catch(Exception e){e.printStackTrace ();} r2h{#2
} X npn{
OrG1Mfx&2%
w$`[C+L
private void processErrorCode(int nErrorCode) ],?$&
{ 3RbPc8($Y
System.err.println("Error Code : " + nErrorCode); neLQ>WT L
} ^KlW"2:
yJ0q)x sS
J*%XtRio
//停止文件下载 8.Z9 i
public void siteStop() ;z Qrree#
{ o@5zf{-
bStop = true; btG+Ak+K*
for(int i=0;i<nStartPos.length;i++) #?3oGrS Y
fileSplitterFetch.splitterStop(); ]cKxYX)J
'{-7%>`bn
ntZl(]l
} #Yd'Vve
} l`mNOQ@}'
//负责部分文件的抓取 8Ry%HV9VE
**FileSplitterFetch.java EE,57(
*/ $~h\`vF&
package NetFox; Vw@?t(l>
gfPR3%EXs
'xG:v)(
import java.io.*; CAJ]@P#Xj+
import java.net.*; Y3n6y+Uzk
Y}n$s/O:u8
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public class FileSplitterFetch extends Thread { xG7/[ jG
^U8^P]{R|
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String sURL; //File URL 8TE2q Pm
long nStartPos; //File Snippet Start Position 0Mo?9??
long nEndPos; //File Snippet End Position }2!=1|}
int nThreadID; //Thread's ID JtbwY@R
boolean bDownOver = false; //Downing is over |ctcY*+
boolean bStop = false; //Stop identical zF7*T?3b"
FileAccessI fileAccessI = null; //File Access interface k^i\<@v
YqEB%Y~N+
>"/Sa_w
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C25EIIdRb
{ vMHJgpd&j
this.sURL = sURL; LJ{P93aq`^
this.nStartPos = nStart; {;2Gl$\r
this.nEndPos = nEnd; D=^|6}
nThreadID = id; i^Ip+J+[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P2t9RCH
} )J>-;EYb8
"BvAiT{u
2zlBrjk;
public void run() N,0&xg3
{ p_:bt7 B
while(nStartPos < nEndPos && !bStop) "0sk(kT
{ 6|@\\\l
1:j[p=Q&
U(~d^9/#
try{ nvOJY6)$V
URL url = new URL(sURL); sVNM#,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h3YWqSj
httpConnection.setRequestProperty("User-Agent","NetFox"); ?H0"*8C?Y
String sProperty = "bytes="+nStartPos+"-"; 5bHS|<
httpConnection.setRequestProperty("RANGE",sProperty); gY/p\kwsj
Utility.log(sProperty); H3Zsm)+:
2l.qINyz
IPa)+ ZQ
InputStream input = httpConnection.getInputStream(); ;%YAiW8{Xk
//logResponseHead(httpConnection); y7@q]~%
of<(4<T
%-Oo92tP
byte[] b = new byte[1024]; "74Rn"d5
int nRead; 3o.9}`/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i[N=.
{ @@pI>~#zh
nStartPos += fileAccessI.write(b,0,nRead); =hq+9 R8=
//if(nThreadID == 1) #k/NS
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [:"7B&&A
} *,y .%`o
7@u:F?c
'g#EBy
Utility.log("Thread " + nThreadID + " is over!"); 7|Bg--G1
bDownOver = true; "b `R_gG9
//nPos = fileAccessI.write (b,0,nRead); (O`2$~mIM
} 0w9[Z
catch(Exception e){e.printStackTrace ();} )oCb9K:km
} vNIQ1x5Za
} 7dq*e4z)
# M18&ld,r
h3BDHz,
//打印回应的头信息 qP4vH]
public void logResponseHead(HttpURLConnection con) 6_a~ 4_#
{ EpdSsfDP
for(int i=1;;i++) }\oy%]_mY
{ UtzM+7r@
String header=con.getHeaderFieldKey(i); Z%9_vpWc
if(header!=null) ]R%+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); fKkH [
Utility.log(header+" : "+con.getHeaderField(header)); d'UCPg<Y
else Cj3C%W
break; >sl#2,br
} -+,3aK<[
} Jd-u?
7>$&CWI
f~-Ipq;F
public void splitterStop() ]IeyJ
{ VqBb=1r%o7
bStop = true; @@~Ql
} L>>Cx`ASi
tv\_& ({
>og- jz
} `44 }kkBT
m6iQB\ \
+S C;@'
/* [~UCYYl
**FileAccess.java Izr_]%
*//文件访问(定位，写) HTw7l]]
package NetFox; O$,bNu/g
import java.io.*; z]33_[G1U
P(Wr[lH\y
rFl6xM;F
public class FileAccessI implements Serializable{ 04}" n
)D>= \Me
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *wNO3tP't
RandomAccessFile oSavedFile; Di>B:=
long nPos; T(4OPiKu
KXvBJA$
[)KLmL%
public FileAccessI() throws IOException ZgH(,g,TU
{ RM `zxFn
this("",0); XPd@>2
} r.#"he_6!.
_+NM<o#A
YfZ96C[a
public FileAccessI(String sName,long nPos) throws IOException f>kW\uC
{ i?D KKjN$
oSavedFile = new RandomAccessFile(sName,"rw"); CF0i72ul5
this.nPos = nPos; jp|1S^b
oSavedFile.seek(nPos); +u|p<z
} SZ3UR
wbA<G&h~
d@#wK~I
public synchronized int write(byte[] b,int nStart,int nLen) /\e&nYz
{ f'Cx%
int n = -1; b@ S.
try{ Z`{ZV5
oSavedFile.write(b,nStart,nLen); %K7wScz7
n = nLen; X$(Dem
} D5gDVulsh
catch(IOException e) w</qUOx
{ ,p7W4;?4
e.printStackTrace (); 4y|%Oj
} w$%1j+%&
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+204.Yj?D
return n; jt,dr3|/n
} ^mZeAW
H(,D5y`k1
V3t;V-Lkt
} nLcOz3h
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KVA~|j B
/* AttS?TZr
**SiteInfoBean.java /@`kM'1:
*/ Dg~L"
package NetFox; Z@d(0 z
B>XfsZS
Ir\f_>7
public class SiteInfoBean { RhQ[hI
3X#)PX9b){
3wf&,4`EX
private String sSiteURL; //Site's URL y L|'K}
private String sFilePath; //Saved File's Path 9fQFsI
private String sFileName; //Saved File's Name 3sF^6<E
private int nSplitter; //Count of Splited Downloading File hCFgZiH2
O[RivHCY
yK"T5^o
public SiteInfoBean() M#a1ev
{//nSplitter的缺省值为5 1xsIM'&
//default value of nSplitter is 5 s%xhT
this("","","",5); e_Un:r@)
} lS!uL9t.
x-%4-)
?Ja&LNI9S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E Zh.*u@^r
{ io^L[
sSiteURL= sURL; 'j27.Ry.
sFilePath = sPath; 2(5<Wj"
sFileName = sName; LzE$z,
this.nSplitter = nSpiltter; &w7Ev21
*Tyr
66 @#V
} I`-N]sf^
@&fAR2
?Q#yf8
public String getSSiteURL() Q-7C'|
{ zC<k4[.
return sSiteURL; 4/:}K>S_
} vWpoaz/w
BfOQ/k))
PTZ/jg@71
public void setSSiteURL(String value) Z?"f#
{ 'PK;Fg\
sSiteURL = value; |'ML )`c[
} Fx6]x$3
>xB[k-C4
"Di8MMGOY
public String getSFilePath() fqp!^-!X
{ TP R$oO2
return sFilePath; f:hsE
} wR]jJbF
?CU6RC n
mA2L~=v#
public void setSFilePath(String value) OJ!=xTU%h
{ sfKu7puc
sFilePath = value; (Xv'Te?
} 4SDUTRoa
S;L=W9=wby
bpp{Z1/4
public String getSFileName() .0]\a~x
{ 6zR9(c:a~
return sFileName; (RBzpAiH
} ^T&@(|o
AAW])c`.
/|MHZ$Y9w?
public void setSFileName(String value) LfsqtQ=J`
{ aTLu7C\-e
sFileName = value; INjr$'*
} 8;\
m]Gxep0%
ewrs D'?
public int getNSplitter() x,81#=m^h
{ ::`#qa4!
return nSplitter; jRGslak;
} XV %DhR=
|9'`;4W
kfj)`x
public void setNSplitter(int nCount) X"Ca
{ dgp1B\
nSplitter = nCount; 3[F9qDAy
} qSA]61U&
} cN3!wE
CyXFuk!R
'nRoa7v(
/* 0*^>/*
**Utility.java EJ@&vuDd$
*/ HzQY\Y6
package NetFox; iKM!>Fi
#AO?<L
pB5#Ho>S
public class Utility { ATzFs]~K;
dn1Fwy.
?%A9}"q]
public Utility() ;Y9-0W
{ ?[VL 2dP0
#UesXv
,7h0y
} "zZZ h
bGtS! 'I
//线程睡眠 X 7R&>Pf
public static void sleep(int nSecond) z)Gd3C
{ DmtCEKa
try{ RIdh],-
Thread.sleep(nSecond); +=MN_
} N> jQe
catch(Exception e) C116c"
{ j@u]( nf
e.printStackTrace (); vN9R.R
} cMK}BHOC
} U-U"RC>
9_-6Lwj6t
//日志 8yDe{
public static void log(String sMsg) Rl{e<>O\^
{ B&L-Lc2
System.err.println(sMsg); v2l*n
} cw3j&k
W7#dc89}
8vqx}2
public static void log(int sMsg) vdIert?p
{ ? FlQ\q
System.err.println(sMsg); S7 !;Z@
} NH'Dz6K5
} zvbO q
bYUG4+rD
'W*:9wah
/* b[KZJLZ)
**TestMethod.java ,n3e8qd
*/ _J"fgxW
package NetFox; aY-7K._</
%E2b{Y;
~JQ6V?fucD
public class TestMethod { p|+TgOYOc
`Kbf]"4q
8+@j %l j
public TestMethod() hQ ?zc_3
{ ///xx/weblogic60b2_win.exe fSF_O}kLp
try{ gY&WH9sp?9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 43?uTnX/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,GF]+nI89
SiteFileFetch fileFetch = new SiteFileFetch(bean); 19b@QgfWpb
fileFetch.start(); es^@C9qt
} 74r$)\q
catch(Exception e){e.printStackTrace ();} FrC)2wX
*7o@HBbF
wZfY~
} q ;"/i*+3
7epil
t0_4jVt
public static void main(String[] args) bae;2| w
{ Y'<wE2ZL)
new TestMethod(); 3Fw7q"
} :cvT/xhO
} MY}/h@
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