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)); [b3!H{b#
} \#9LwC"8;
for(int i=0;i<nEndPos.length-1;i++) MuY:(zC%
{ %PYl
nEndPos = nStartPos[i+1]; crM5&L9zF
} 4!Js="
nEndPos[nEndPos.length-1] = nFileLength; %hnBpz
} r<+C,h;aww
} a+^`+p/5
AatSN@,~z
[MTd<@
//启动子线程 !LN8=u.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jfxNV2[
for(int i=0;i<nStartPos.length;i++) wX"hUu
{ 4qOzjEQ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !wy _3a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), i<Vc~!pT
nStartPos,nEndPos,i); n N<N~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t/iI!}
fileSplitterFetch.start(); b&z#ZY
} lYx_8x2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zo3!Hs ZA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a$My6Qa#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bBjr hi
nEndPos = " + nFileLength); A>@#eyB
// fileSplitterFetch[nPos.length-1].start(); ]ZY2\'
p27Dcwov
bWswF<y-
//等待子线程结束 JmI%7bH@
//int count = 0; } !m43x/&
//是否结束while循环 Ww]$zd-bo
boolean breakWhile = false; rQjk
<>] DcA
uk):z$x
while(!bStop) HbKE;N
{ +MoUh'/u
write_nPos(); hhTtxC<:
Utility.sleep(500); E=sh^Q(A
breakWhile = true; TjW!-s?S
`fBQ?[05.
/%T/@y
for(int i=0;i<nStartPos.length;i++) !m@cTB7i
{ fzSkl`K}
if(!fileSplitterFetch.bDownOver) /7AHd ;
{ MpCPY"WLL
breakWhile = false; nQF&^1n
break; Qd}n4KF\
} @Kpm&vd(
} ;vH2r~
if(breakWhile) c+:ZmrP/
break; .hT>a<
n2U &}O
%F*9D3^h
//count++; 1b5Z^a<u
//if(count>4) &tyS6S+
// siteStop(); (t4i&7-
} Oyl~j#h
B"^j>SF
6$`<Y?
System.err.println("文件下载结束！"); [EAOk=X
} _jQ:9,; A
catch(Exception e){e.printStackTrace ();} iM]O
} L AQ@y-K3
7+jxf[(XQ
q)q3p
//获得文件长度 d<m;Q}/l&h
public long getFileSize() CNB weM
{ I,?NYIG"(
int nFileLength = -1; m06'T2I
try{ VI! \+A
URL url = new URL(siteInfoBean.getSSiteURL()); 9[eiN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bxXpw&
httpConnection.setRequestProperty("User-Agent","NetFox"); GkAd"<B
-X.#Y6(
14,)JZN
int responseCode=httpConnection.getResponseCode(); UTA|Ps$
if(responseCode>=400) {53FR
{ H=/1d.p
processErrorCode(responseCode); Hv/C40uM-
return -2; //-2 represent access is error eR!#1ar
} JYdb^j2c
FnGKt\
b_x!m{
String sHeader; 1iT_mtXK$
j+jC J<
j*%#~UFw
for(int i=1;;i++) Pf;OYWST
{ MK#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 9ihg[k
//Utility.log(in.readLine()); gwj?.7N*k
sHeader=httpConnection.getHeaderFieldKey(i); 8lF9LZ8
if(sHeader!=null) }QE.|.fA1
{ ;}B=g/C
if(sHeader.equals("Content-Length")) "*lx9bvV_
{ ZU\$x<,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Kzev] er
break; ,:S#gN{U
} F/v.hP_
} (:iMs) iO{
else \mb4leg5
break; c&c
} 8lk/*/} =<
} *l7 `C)
catch(IOException e){e.printStackTrace ();} P]+B}))
catch(Exception e){e.printStackTrace ();} `,O7S9]R+
{z oGwB
%Wtf24'o;v
Utility.log(nFileLength); =ejcP&-V/
F8%^Ed~@
xF_u:}7`
return nFileLength; 6~dAK3v5
} O"\4[HE^
S^s-md>
XDK Me}
//保存下载信息（文件指针位置） _`2%)#^o
private void write_nPos() :!i=g+e]
{ cS.@02~f"
try{ g~<[;6&{
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1d<?K7%^
output.writeInt(nStartPos.length); `^#Rwn#
for(int i=0;i<nStartPos.length;i++) U&3!=|j
{ Y{dSQ|xz^
// output.writeLong(nPos); C|y^{4|R
output.writeLong(fileSplitterFetch.nStartPos); 7w73,r/D8A
output.writeLong(fileSplitterFetch.nEndPos); e1[ReZW
} '6D"QDZB
output.close(); c&;" Y{
} MR "f)
catch(IOException e){e.printStackTrace ();} 8GkWo8rPk
catch(Exception e){e.printStackTrace ();} k}LIMkEa4a
} /KH85/s
pj%]t
Zbo4{.#
//读取保存的下载信息（文件指针位置） ZK4V-?/[6
private void read_nPos() 7(/yyZQnZ
{ $HwF:L)*
try{ O72g'qFPE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -zECxHjx
int nCount = input.readInt(); CH7a4qL`
nStartPos = new long[nCount]; AMrYT+1
nEndPos = new long[nCount]; PTHxvml
for(int i=0;i<nStartPos.length;i++) /l`zZ>
{ s}JifY`
nStartPos = input.readLong(); 'v'[_(pq
nEndPos = input.readLong(); 0LW3VfvToN
} u?>},M/
input.close(); 8jCho
} 9DBX.|
catch(IOException e){e.printStackTrace ();} ij:xr% FJ
catch(Exception e){e.printStackTrace ();} ,DEq"VW_
} .BxI~d^
b GSj?t9/
wPI!i K@Ro
private void processErrorCode(int nErrorCode) **P P
{ zd$'8/Cq
System.err.println("Error Code : " + nErrorCode); 8 n[(\f:
} MTt8O+J?P~
vU *: M8k
x|Uwk=;X|s
//停止文件下载 )d[n-Si
public void siteStop() jP+{2)z"W
{ cLyf[z)W
bStop = true; %lbvK^
for(int i=0;i<nStartPos.length;i++) 3MX#}_7A
fileSplitterFetch.splitterStop(); pg5W`4-F
cRI2$|
4+8)0;<H
} S^R dj ]
} @ws&W=NQ
//负责部分文件的抓取 JQb{?C
**FileSplitterFetch.java e=XP4h
*/ e&ti(Q=
package NetFox; \=({T_j4
uou "s9
USART}Us4
import java.io.*; t7-r YY(
import java.net.*; ~_BjcY
7 @\i5
p` ~=v4;b
public class FileSplitterFetch extends Thread { "3_X$`v"!
t=lDN'\P
NvzPZ9=@-
String sURL; //File URL &fRz6Hd
long nStartPos; //File Snippet Start Position Na`> pH
long nEndPos; //File Snippet End Position NxJnU<g-
int nThreadID; //Thread's ID h_-4Q"fb(
boolean bDownOver = false; //Downing is over FVNTE+LW
boolean bStop = false; //Stop identical q%d,E1
FileAccessI fileAccessI = null; //File Access interface lDBAei3iB
YuuTLX%3
^coCsV^CW"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7cV G?Wr
{ +Zi+ /9Z(H
this.sURL = sURL; )Q9Qo)D T
this.nStartPos = nStart; = y^5PjN
this.nEndPos = nEnd; o(}%b8 K
nThreadID = id; 8(ZQM01;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kjQW9QJ<
} &qY]W=9uK
XX-(>B0L
(k+*0.T&?
public void run() AyUw
{ z}}P+P/
while(nStartPos < nEndPos && !bStop) "+2Cs
{ ?9?A)?O<j~
7oZPb
/7#MJH5b6
try{ :}36;n<['
URL url = new URL(sURL); {1=|H$wKg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Xz:ha>}C
httpConnection.setRequestProperty("User-Agent","NetFox"); l4mRNYv)z
String sProperty = "bytes="+nStartPos+"-"; W*iTg%a\k
httpConnection.setRequestProperty("RANGE",sProperty); ]Ndy12,M
Utility.log(sProperty); S~r75] "
IAbQgBvUD
>r X$E<B\
InputStream input = httpConnection.getInputStream(); NHUJ:j@
//logResponseHead(httpConnection); 1mHS -oI9J
}.s%J\ckx
S/*\j7cj
byte[] b = new byte[1024]; @gqZiFM)
int nRead; Rkg)yme!N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) An}RD73!w
{ AEM;ZQU
nStartPos += fileAccessI.write(b,0,nRead); vr"Pr4z4i
//if(nThreadID == 1) dHAT($QG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ic}TiTK
} o6w8Y/VPu
a Z)1SX`D
CN` ~DD{
Utility.log("Thread " + nThreadID + " is over!"); S;t`C~l\
bDownOver = true; Y>C05?>
//nPos = fileAccessI.write (b,0,nRead); \^pc"?Rc
} dYOY8r/
catch(Exception e){e.printStackTrace ();} Mb"y{Fox
} k8J zey]X
} oM>UIDCY_v
{m3#1iV9
J:'_S `J
//打印回应的头信息 C(h<s e?
public void logResponseHead(HttpURLConnection con) i@D4bd9lR
{ #?\(l%
for(int i=1;;i++) 7MZH'nO
{ ,j{tGj_
String header=con.getHeaderFieldKey(i); EF$ASNh"
if(header!=null) Q3hSWXq'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]5@n`;&#.
Utility.log(header+" : "+con.getHeaderField(header)); OpazWcMoo
else a0k;way
break; ]iW:YNvXA
} QoUdTIIL
} _R]0S
}M(xN6E
y:Gn58\o
public void splitterStop() ?Hdu=+ZV
{ ) x+edYw
bStop = true; n(V{ [
} aso8,mpZuA
nVoWER:
_pb*kJ
} 8G$BQ
<L*`WO]\l
jPo,mz&^
/* zp:QcL"
**FileAccess.java ~s-gnp
*//文件访问(定位，写) tBJ4lb
package NetFox; RcJtVOrd
import java.io.*; a {x3FQ
Yj bp:
1_!?wMo:f
public class FileAccessI implements Serializable{ 0#=xUk#LP`
7f k)a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~a4Y8r
RandomAccessFile oSavedFile; ex`T9j.=B
long nPos; ~uq010lMno
`YwJ.E
}%PK %/ zI
public FileAccessI() throws IOException o_b3G
{ rZ n@i
this("",0); >r\GB#\5
} mT-[I<
$aU.M3
JvvN>bg
public FileAccessI(String sName,long nPos) throws IOException j[R.UB3J
{ S[7^#O.)
oSavedFile = new RandomAccessFile(sName,"rw"); tw.GBR
this.nPos = nPos; *aS+XnT/
oSavedFile.seek(nPos); jTg~]PQ^
} 5_](N$$
~Gh7i>n*
1anh@T.
public synchronized int write(byte[] b,int nStart,int nLen) 479X5Cl
{ M?My+oT
int n = -1; __7}4mA
try{ .hG*mXw>
oSavedFile.write(b,nStart,nLen); )qMbk7:v\
n = nLen; opm_|0
} jDQ?b\^
catch(IOException e) EFx>Hu/[G
{ 'nM4t
e.printStackTrace (); Ye$j43b
} sCt)Yp+8}B
9M($_2,44
:2M&C+f[
return n; 'Nt)7U>oC9
} *U%3[6hm
))Z>$\<:
vR!g1gI23
} Wq+GlB*
yZ[g2*1L
"@hd\w{.
/* eCsk\f`
**SiteInfoBean.java Z|x|8 !D
*/ LWTPNp:"{w
package NetFox; RjvW*'2G
=9 )k:S(
ZQfPDH=
public class SiteInfoBean { y9d"sqyh
`#l3a
(57!{[J
private String sSiteURL; //Site's URL [|c%<|d2
private String sFilePath; //Saved File's Path j-R*!i
private String sFileName; //Saved File's Name y2jw3R
private int nSplitter; //Count of Splited Downloading File 3TCRCz
Ic_NQ<8
>l AtfN='
public SiteInfoBean() _h#I}uJ~
{//nSplitter的缺省值为5 &qdhxc4
//default value of nSplitter is 5 A&Aj!#
this("","","",5); 0mUVa=)D
} g;p} -=
9NU0K2S
Kw?3joy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /u.ZvY3,
{ 3BCD0 %8
sSiteURL= sURL; jMTM:~0N
sFilePath = sPath; /N_:npbJF
sFileName = sName; LOi}\O8
this.nSplitter = nSpiltter; RQo a
<]1,L%
K6-M.I
} J=$\-
TE+>|}]R
rqmb<# Z
public String getSSiteURL() egG<"e*W}N
{ U7D!w$4
return sSiteURL; &5R|{',(Y
} 'n,V*9
ML\>TDt
=iKl<CqI$E
public void setSSiteURL(String value) cXqYO|3/M
{ C[ mTVxd
sSiteURL = value; kq5X<'MM9N
} P* `*^r3
1,;X4/*
p+V#86(3
public String getSFilePath() J,CwC)
{ \|{/.R
return sFilePath; rfEWh Vy(}
} f!#!
%Rn*oV
S=mqxIo@m
public void setSFilePath(String value) lh"*$.j-
{ c'eZ-\d{
sFilePath = value; m:?"|.]
} (XVBH1p"
oXnaL)Rk
z.SC^/\o|
public String getSFileName() bqAW
{ [#q>Aq$11
return sFileName; W~ET/h
} (n*:LS=0
LQ# E+id&
C{zp8 A(Dh
public void setSFileName(String value) [rT.k5_
{ s4"OsgP+
sFileName = value; -<6?ISF2
} v wEbGx
nlNk
b[<RcM{r}
public int getNSplitter() ~.%HZzR6&
{ <ErX<(0`ig
return nSplitter; )|lxzlk
} l,4O
~x9]?T
zd=O;T;.
public void setNSplitter(int nCount) ?qaWt/m
{ ]oB~8d
nSplitter = nCount; ]h,rgO;
} L\PmT
} clB K
Q- |Y
s;Gd`-S>d
/* ">oySo.B?
**Utility.java T^1 Z_|A
*/ 8#7qHT;cx
package NetFox; + t5SrO!`
Tf86CH=)5
_VKI@
public class Utility { *i]?J
IFp%Ta
m$W>~
public Utility() E&P2E3P
{ C_Ewu*T7
gYB!KM *v
3=YpZ\l}
} __g k:a>oQ
-r={P_E6
//线程睡眠 X/,)KTo7
public static void sleep(int nSecond) }4A] x`3
{ qSc-V`*
try{ vQljxRtW
Thread.sleep(nSecond); 7 $e6H|j@
} CF '&Yo
catch(Exception e) C!VhVOy>d
{ Q\N*)&Sd<M
e.printStackTrace (); r=H?fTY<3E
} ?RsrY4P
} J-v1"7[2GC
XMrk2]_
//日志 aOwjYl[?p
public static void log(String sMsg) \Oeo"|
{ B.q/}\ ?(
System.err.println(sMsg); Ktq4b%{
} 5#K*75>
M^o_='\bE
SiLW[JXd
public static void log(int sMsg) DiFYVR<@
{ }KI/fh
System.err.println(sMsg); .<"XE7
} =nhY;pY3u
} [7Lr"
dHc\M|HCC
+OE!Uqnt
/* !D#"+&&G8
**TestMethod.java hmu>s'
*/ 7Y5r3a}%
package NetFox; {zwH3)|Hn
ngo> ^9/8
n)e2?
public class TestMethod { nkW})LyB\
vI{aF- #
(pxH<k=Ah
public TestMethod() .XJ'2yKof
{ ///xx/weblogic60b2_win.exe 7n7Xyb
try{ XX8HSw!w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3uLG$`N
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); q+?<cjVg
SiteFileFetch fileFetch = new SiteFileFetch(bean); VdlT+'HF
fileFetch.start(); eZ$7VWG#
} &93{>caf+
catch(Exception e){e.printStackTrace ();} 7Sx|n}a-3
z'YWomfZm
,;$OaJFT
} gP2zDI
tT}b_r7h(1
jn<?,UABD
public static void main(String[] args) uX_H;,n
{ w% %q/![uy
new TestMethod(); ~g{j)"1
} *~vB6V|1
} v:t;Uk^Y
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