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)); %upnXRzw
} EkS7j>:
for(int i=0;i<nEndPos.length-1;i++) hyqsMkW|
{ !m)P*Lw
nEndPos = nStartPos[i+1]; >Q':+|K}
} SZW+<X
nEndPos[nEndPos.length-1] = nFileLength; M il ![A1
} +Gv{Apd"
} 2gLa4B-
&(a#I]`9M
a'=C/ s+
//启动子线程 ^{\gD23
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 72@lDY4cE
for(int i=0;i<nStartPos.length;i++) c#X9d8>
{ SJ$N]<d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _X5@%/Vz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9fp@d
nStartPos,nEndPos,i); LnZzY0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qd\5S*Z1
fileSplitterFetch.start(); "e.QiK
} 8Yfg@"Tn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l`D^)~o8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ."9t<<!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s*$Re)}S
nEndPos = " + nFileLength); JRQ{Q"`)
// fileSplitterFetch[nPos.length-1].start(); z*?-*6W
<%WN<T{q|
-=_bXco}
//等待子线程结束 *PQu9>1w
//int count = 0; PR rf$& u
//是否结束while循环 PAG.],"D
boolean breakWhile = false; b=[gK|fu
pm$ZKM
W'2T7ha Es
while(!bStop) ANB@cK_
{ LB*qL
write_nPos(); z~tCag8I(k
Utility.sleep(500); x;A"S
breakWhile = true; Exir?G}\
0].x8{~o
g%()8QxE1
for(int i=0;i<nStartPos.length;i++) aRFLh
{ 01v7_*'R
if(!fileSplitterFetch.bDownOver) C'8v\C9Ag
{ ShXk\"
breakWhile = false; |<nS<x
break; mEi+Tj zp
} r(sQI# P
} ::13$g=T9s
if(breakWhile) WT(inf[
break; 'u@_4wWp
K:PzR,nn
Xk#"rM< Y
//count++; [Xp{ztGE
//if(count>4) yn&AMq ]o
// siteStop(); =%u\x=u|
} RQ?T~ASs
a[TR_uR
gucd]VH
System.err.println("文件下载结束！"); <~aQ_l
} >r Nff!Ow
catch(Exception e){e.printStackTrace ();} en\shc{R]`
} Qd~M;L O"i
?Y6MC:l<
+rEqE/QF
//获得文件长度 >dH5n$Gb
public long getFileSize() rEI]{?eoF
{ g=eYl_P6
int nFileLength = -1; NOOP_:(7H
try{ :,.g_@wvG
URL url = new URL(siteInfoBean.getSSiteURL()); M6n9>aW4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KP)BD;
httpConnection.setRequestProperty("User-Agent","NetFox"); iUuG}rqj
-$pS {q;
]W,K}~!
int responseCode=httpConnection.getResponseCode(); >z0~!!YZ
if(responseCode>=400) /<Nb/#8
{ m5KB#\
processErrorCode(responseCode); ~50b$];y
return -2; //-2 represent access is error &{B-a
} oZvQ/|:p!
d~L`*"/)[
1_JxDT,=>
String sHeader; wg6![Uh
.0x+b-x
urGk_.f
for(int i=1;;i++) wk {9
{ q|PB[*T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QusEWq)}<
//Utility.log(in.readLine()); xl5n(~g)p
sHeader=httpConnection.getHeaderFieldKey(i); >`rK=?12<
if(sHeader!=null) }qUNXE@
{ 6bL+q`3>
if(sHeader.equals("Content-Length")) 7?6?`no~JJ
{ )k5lA=(Yr+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /a7tg+:
break; ,e"A9ik#
} yQwj[
} c"aiZ(aP
else j!r4p,
break; Ph&AP*Fq
} 3[Pa~]yS
} YxMOr\B
catch(IOException e){e.printStackTrace ();} ]a% *$TF
catch(Exception e){e.printStackTrace ();} T!6H5>zA
f_1#>]
L2ePWctq}
Utility.log(nFileLength); !Ju?REH
2A3;#v
\Cx) ~bq<
return nFileLength; <YbOO{
} $)| l#'r
W(*:8}m,p
e_J_rx
//保存下载信息（文件指针位置） 9kPwUAw
private void write_nPos() oF/5mh__(K
{ '< OB j
try{ H~-zq}4
output = new DataOutputStream(new FileOutputStream(tmpFile)); RVN"lDGA
output.writeInt(nStartPos.length); %UJ!(_
for(int i=0;i<nStartPos.length;i++) .vRLK
{ &J|3uY,'j
// output.writeLong(nPos); 3j.Ft*SV
output.writeLong(fileSplitterFetch.nStartPos); ]UnZc
output.writeLong(fileSplitterFetch.nEndPos); Xu#\CYk
} gF%lwq
output.close(); L1u
} Auhw(b>}TW
catch(IOException e){e.printStackTrace ();} w<_.T#
catch(Exception e){e.printStackTrace ();} fys@%PZq
} qs6yEuh#
<!:,(V>F(C
p$}iBk0B(z
//读取保存的下载信息（文件指针位置） -@ #b<"1
private void read_nPos() <[xxCW(2
{ GY4:9Lub7
try{ p7(xk6W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ty%4#9``0
int nCount = input.readInt(); (]0$^!YK
nStartPos = new long[nCount]; R!xs;|]
nEndPos = new long[nCount]; )!MeSWGq
for(int i=0;i<nStartPos.length;i++) '<f4POy!
{ TyMRm
nStartPos = input.readLong(); ?8Cxt|o>
nEndPos = input.readLong(); )rD] y2^<
} !@-j!Ub
input.close(); !B?/6XRUx
} NFGC.<
catch(IOException e){e.printStackTrace ();} Ns9cx
catch(Exception e){e.printStackTrace ();} !U#kUj:4I
} `"[VkQFB/
aPB %6c=
o_U=]mEDY
private void processErrorCode(int nErrorCode) 9;Ezm<VQ
{ 'DF3|A],
System.err.println("Error Code : " + nErrorCode); !-r@_tn|
} s)yEVh
zsI0Q47\
T4T_32`XR
//停止文件下载 '9GHmtdO,
public void siteStop() kgK7 T
{ AW6]S*rh
bStop = true; v:CYf_
for(int i=0;i<nStartPos.length;i++) YP~d1BWvf
fileSplitterFetch.splitterStop(); -$;H_B+.
C 0*k@kGy
6KhHS@Z
} 8E/$nRfOd
} J),7ukLu^
//负责部分文件的抓取 c[<lr
**FileSplitterFetch.java [w~teX0!
*/ N;D(_:^
package NetFox; OM]p"Jd
{AIP\
<(d^2-0
import java.io.*; 1*?IDYB
import java.net.*; N!;Y;<Ro_
E?z 3&C
FqsG#6|x
public class FileSplitterFetch extends Thread { i>T{s-3v
/'E+(Y&:J
$${ebt
String sURL; //File URL c@ En4[a'
long nStartPos; //File Snippet Start Position *ok89ad
long nEndPos; //File Snippet End Position ]V]~I.
int nThreadID; //Thread's ID 6\O4R
boolean bDownOver = false; //Downing is over -O~WHi5}
boolean bStop = false; //Stop identical |IH-a"
FileAccessI fileAccessI = null; //File Access interface 0"u*Kn
qChS} Q
J~ v<Z/gm
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]G&?e9OA
{ jb)z[!FbM
this.sURL = sURL; P>L-,R(7e
this.nStartPos = nStart; OdRXNk:k-j
this.nEndPos = nEnd; 9|jIrS%/~
nThreadID = id; _w+sx5
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rf;R"Uc
} VjYfnvE
30FYq?
RNoS7[&
public void run() ,k{{ZP P
{ \I#lLP
while(nStartPos < nEndPos && !bStop) UN|"D]>/
{ ]ZO^@sH
\R&`bAdk
K]@6&H-b|
try{ 2|EHNy!
URL url = new URL(sURL); BAmH2"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6$SsdT|8B
httpConnection.setRequestProperty("User-Agent","NetFox"); D8`,PXtV
String sProperty = "bytes="+nStartPos+"-"; '4HwS$mW3
httpConnection.setRequestProperty("RANGE",sProperty); U@D=.6\B
Utility.log(sProperty); }'kk}2ej`
]|Vm!Q
L4.yrA-]C%
InputStream input = httpConnection.getInputStream(); bvEk.~tC'
//logResponseHead(httpConnection); *KxV;H8/
Jd1eOeS
D6bCC; h=
byte[] b = new byte[1024]; 'ycs{}'
int nRead; `{F8#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ),bdj+wr78
{ ^fnRzX
nStartPos += fileAccessI.write(b,0,nRead); uHz D
//if(nThreadID == 1) X/5tZ@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,X$S4>
} M/d!&Bk
9]NsWd^^
xZ`t~4qR
Utility.log("Thread " + nThreadID + " is over!"); 'r1&zw(
bDownOver = true; |V!A!tB
//nPos = fileAccessI.write (b,0,nRead); ,dBtj8=
} b^Rg_,s
catch(Exception e){e.printStackTrace ();} !6<2JNf
} ^N Et{]x
} ]o,)#/' $
aM?7'8/
'-w G
//打印回应的头信息 J_rCo4}
public void logResponseHead(HttpURLConnection con) EF)kYz!@
{ c~RElL
for(int i=1;;i++) \FVR'A1
{ =\X<UA}
String header=con.getHeaderFieldKey(i); oH6(Lq'q
if(header!=null) n6Q 3X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cY\-e?`=4
Utility.log(header+" : "+con.getHeaderField(header)); [`ttNW(_
else ,Hys9I
break; Qg9{<0{u
} ~Gwn||g78
} gvA&F|4
Htsa<tF
(CZRX9TT1
public void splitterStop() lzS"NHs<g(
{ kf"cd1
bStop = true; Vx* =
} r)X?H
%5F=!(w
*WX6C("M
} b;soMilz
wy) Frg
%HYC-TF#
/* I &{dan2
**FileAccess.java ZP%^.wxC
*//文件访问(定位，写) 5^* d4[&+
package NetFox; [&+wW
import java.io.*; @ULr)&9
aN;L5;m#>{
ZV;#ZXch
public class FileAccessI implements Serializable{ 'Iu$4xo`[
xO?~@5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cE]tvL:g
RandomAccessFile oSavedFile; zI7-xqZ
long nPos; 1/le%}mK
mi97$Cr2
(x.K%QC)
public FileAccessI() throws IOException KsUsj3J
{ %j^=
this("",0); Atfon&^
} GVEjB;
I[[rVts
"me Jn/
public FileAccessI(String sName,long nPos) throws IOException GueqpEd2
{ I"@5=m5
oSavedFile = new RandomAccessFile(sName,"rw"); KY|Q#i|pM
this.nPos = nPos; [xI@)5Xk
oSavedFile.seek(nPos); Y/@4|9!
} _v2FXm
^vG*8,^S=8
8swj'SjX
public synchronized int write(byte[] b,int nStart,int nLen) 2^UFP+Yw
{ ]^Q`CiKd
int n = -1; x5PQ9Bw,
try{ "F%cn@l
oSavedFile.write(b,nStart,nLen); vRT1tOQ$
n = nLen; %X[|7D-
} _Dk;U*2
catch(IOException e) zD)2af
{ b,318R8+G
e.printStackTrace (); n$b/@hp$z
} m! p'nP
|(S=G'AtU
CiPD+I
return n; c>DAR
} PJ #uYM
u.!Pda
-} Z
} t5eux&C
IOIGLtB
@@# G.
/* 8Cm^#S,+
**SiteInfoBean.java {W0]0_mI(
*/ % ;6e@U}
package NetFox; C=hE@
tb@/E
\>I&UFfH)4
public class SiteInfoBean { )cOm\^,
"&C'K
4H1s"mP<
private String sSiteURL; //Site's URL b(~NqV!i
private String sFilePath; //Saved File's Path 6Ajiz_~U
private String sFileName; //Saved File's Name OkFq>;{a
private int nSplitter; //Count of Splited Downloading File pV>/"K
U<#i\4W
DQ'+,bxk=9
public SiteInfoBean() vx-u+/\
{//nSplitter的缺省值为5 P5aHLNit
//default value of nSplitter is 5 <ygkK5#q
this("","","",5); k ( R
} -M[5K/[
k`TEA?RfQ
yl3iU:+V
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PU-;Q@< E
{ U15Hq*8Z
sSiteURL= sURL; yY,.GzIjCj
sFilePath = sPath; YjG0: 9
sFileName = sName; l<qxr.X
this.nSplitter = nSpiltter; ]p#Zdm1EL
KN+*_L-
nTYqZlI,
} }-8K*A3
XPX{c|]>.
q:nYUW o
public String getSSiteURL() ]vu'+F$
{ ;%U`lE0
return sSiteURL; 1>|p1YZ"
} 8vaqj/
MK=:L
v3@)q0@
public void setSSiteURL(String value) >#>YoA@S
{ wmT3 >
sSiteURL = value; BJlF@F#
} 9 -TFyZYU
+%>L;'L ^X
q .?D{[2
public String getSFilePath() LY^BkH'
{ , :kCt=4%
return sFilePath; "w_(p|cm=
} TJO|{Lxm
Gzm[4|nO^
v_G4:tY
public void setSFilePath(String value) gw5CU)r4$
{ S9xC> |<
sFilePath = value; =#>P!
} qLPI^g,
} 10Dvt>+
wePMBL1P*
public String getSFileName() w|$;$a7)
{ + ^~n09
return sFileName; iAXx`>}m
} DpTQPu9
TmUn/
-98bX]8
public void setSFileName(String value) Y3-15:-
{ o]k[l;
sFileName = value; -4HI9Czts
} (r7~ccy4
cLB"<mG
$x`U)pv
public int getNSplitter() XvdK;
{ \W$>EH
return nSplitter; qP]Gl--q{
} ozGK -$
VT0I1KQx.
tM!1oWH
public void setNSplitter(int nCount) OO\UF6MCU
{ 6%fU}si,
nSplitter = nCount; az19-QIcg
} c{&sf y
} 9$Hgh7'hvs
ql_aDoj
`Y+p7*Qr2
/* EcP"GO5
**Utility.java eQYW>z'%,
*/ XFM6.ye
package NetFox; /j.V0%
C0kwI*)
cIq3En
public class Utility { =P2T&Gb
>r{,$)H0
1_<'S34
public Utility() cL`l1:j\}
{ N-vr_4{g
#>!!#e!*
EV~_-YC
} 6Lz&"C,`
Le_?x
//线程睡眠 n1!u aUC
public static void sleep(int nSecond) Yz{UP)TC
{ R=PjLH&)
try{ i%-c/ lop
Thread.sleep(nSecond); AMtFOXx%I
} 33 N5>}
catch(Exception e) TNiFl hq
{ F1MPo;e
e.printStackTrace (); BeP0lZ
} !f"@pR6
} o<%Sr*
R#Ss_y
//日志 F5EKWP
public static void log(String sMsg) b/2t@VlL
{ _D z4}:9
System.err.println(sMsg); ~Uga=&
} vbh\uv&
/A{znE
bC"#.e
public static void log(int sMsg) u QCQ$
{ ;:'A{&0N
System.err.println(sMsg); PBkKn3P3
} 5w{_WR6,
} Jd)|==yD
Z=wLNmH
6B|IbQ^
/* t0hg!_$bq
**TestMethod.java "y5c)l(Rg
*/ MbjH\XRB
package NetFox; x+^iEj`gk
/SP^fB*y
B;_M52-B
public class TestMethod { .K:>`~<)
et)A$'Q
8Gs{Zfp!D
public TestMethod() K{"(|~=U
{ ///xx/weblogic60b2_win.exe Rz%+E0
try{ 'N'EC`R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z?1.Y7Npr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qs</.PO
SiteFileFetch fileFetch = new SiteFileFetch(bean); C3WqUf<8`{
fileFetch.start(); V"\t
} IDwneFO
catch(Exception e){e.printStackTrace ();} QiB:K Pz[
Z\`uI+`
6(X(f;MEl
} %'@&j2j>
QBDi;Xzb+
Q<Utwk?nL
public static void main(String[] args) 5f}wQ
{ !=eui$]
new TestMethod(); ;-U:t4
} +*F ;l\R
} FRX'"gIR0
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