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)); K:mb$YJ&
} \%UA6uj
for(int i=0;i<nEndPos.length-1;i++) C+_ NG
{ _("{fJ,A
nEndPos = nStartPos[i+1]; 8@ b83
} 1Ypru<.)W
nEndPos[nEndPos.length-1] = nFileLength; rQU;?[y
} UPH:$Fk&
} F[LBQI`zq
RX'( l
pl5!Ih6
//启动子线程 M*nfWQ a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |VIBSty2d
for(int i=0;i<nStartPos.length;i++) k z<We/
{ )tB mSVprl
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R4{2+q=0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;L|%H/SH
nStartPos,nEndPos,i); 13Q|p,^R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^$VOC>>9
fileSplitterFetch.start(); E}UlQq
} H13|bM<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dAR):ZKq?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [E+#+-n7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1N2s[ \q$
nEndPos = " + nFileLength); : -OHD#>%
// fileSplitterFetch[nPos.length-1].start(); 99vm7"5hQ
]w({5i
c8A //
//等待子线程结束 BDpeAF8z
//int count = 0; v*kTTaU&
//是否结束while循环 ]*?qaIdqu
boolean breakWhile = false; |:C=j/f
$5l8V
@wbV@
while(!bStop) 88G Q F
{ +v/_R{ M
write_nPos(); 9 u{#S}c`
Utility.sleep(500); t\X5B]EZ
breakWhile = true; z>~Hc8*]3
?Yxk1Y4ig)
jT%k{"+>+?
for(int i=0;i<nStartPos.length;i++) i!9yN:m0
{ K[O'@v
if(!fileSplitterFetch.bDownOver) >J+hu;I5
{ )=#QTiJ
breakWhile = false; ?J|~G{yH
break; k1W q$KCwG
} iXeywO2nP
} zmF_-Q`c
if(breakWhile) F|9 W7
break; Qn_*(CSp
*s}dtJ
"9aiin
//count++; ; 7k@_
//if(count>4) Mz_*`lRN
// siteStop(); -:&qNY:Vp
} /aP4'U8ov
W&qE_r
%&0_0BU
System.err.println("文件下载结束！"); 8V?O=3<a
} HsO4C)/
catch(Exception e){e.printStackTrace ();} \:, dWLu
} Cwl#(;@
0& 54xP
`L/\F,
//获得文件长度 jw]~g+x#$
public long getFileSize() l*rli[No
{ D=i)AZqMPp
int nFileLength = -1; y ~7]9?T
try{ ^^1rjh1I
URL url = new URL(siteInfoBean.getSSiteURL()); QE1DTU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #**vIwX-Q
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Ck'A0d
bd_&=VLTC
0j@gC0xu)|
int responseCode=httpConnection.getResponseCode(); <KlG#7M>
if(responseCode>=400) eX;C.[&7;8
{ CvS}U%
processErrorCode(responseCode); Ksr.'
return -2; //-2 represent access is error ;rC)*=4#
} NBU[>P
e@|/, W
3=SIIMp7=
String sHeader; Hx5t![g2K!
74i
}}y~\TB~}
for(int i=1;;i++) vau0Jn%=ck
{ z)*7LI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >VIb|YA
//Utility.log(in.readLine()); XR3=Y0YDf
sHeader=httpConnection.getHeaderFieldKey(i); kqdF)Wa am
if(sHeader!=null) kwF4I)6
{ 1w*DU9f
if(sHeader.equals("Content-Length")) U51C /A
{ Q4i@y6z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;w--fqxVl
break; Pv,Q*gh`
} x=s=~cu4,
} 5F&xU$$a-
else 8$4@U;Vh;
break; ?(rJ
} SFP%UfM<
} !(QDhnx}9c
catch(IOException e){e.printStackTrace ();} #[=%+*Q
catch(Exception e){e.printStackTrace ();} D; i%J
T$)N2]FE
i^`]TOP
Utility.log(nFileLength); ^FJ.C|l(
y(!J8(yA
`IN/1=]5
return nFileLength; AM?62
} Y_S>S(0
oS.fy31p
7S'3U}Y>VX
//保存下载信息（文件指针位置） cG{>[Lf
private void write_nPos() NFxs4:] RT
{ z86[_l:
try{ :jo !Yi
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9OI&De5?=V
output.writeInt(nStartPos.length); b8o}bm{s
for(int i=0;i<nStartPos.length;i++) /1OzX'5f
{ JzI/kH~
// output.writeLong(nPos); l.gt+e
output.writeLong(fileSplitterFetch.nStartPos); $=) i{kGS@
output.writeLong(fileSplitterFetch.nEndPos); :s(vn Ie^
} 1FC' iGI
output.close(); 1j4(/A
} UM[<v9NWE
catch(IOException e){e.printStackTrace ();} 0{0BL@H
catch(Exception e){e.printStackTrace ();} ^6c=[N$aW
} ?7n(6kmj4Q
uj 6dP
E6 glR
//读取保存的下载信息（文件指针位置） -`knSR
private void read_nPos() x.J% c[Q8
{ k(As^'>
try{ 1"7Rs}l7
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LNm{}VJ%
int nCount = input.readInt(); UTT7a"
nStartPos = new long[nCount]; q4Z9;^S
nEndPos = new long[nCount]; c^Y&4=>T
for(int i=0;i<nStartPos.length;i++) wlvhDJ
{ BM6 J
nStartPos = input.readLong(); AiMD"7 )c
nEndPos = input.readLong(); E}&Z=+v}
} B-EVo&.
input.close(); b d!|/Lk
} 6@N?`6Bt
catch(IOException e){e.printStackTrace ();} pyvZ[R9
catch(Exception e){e.printStackTrace ();} D`|.%
} f/!^QL{
Nw74T
YSQB*FBz
private void processErrorCode(int nErrorCode) tp4/c'w;)J
{ 39j "z8n
System.err.println("Error Code : " + nErrorCode); |gl~wG1@
} !+Ia#(
Yr7%C
MGoYL\
//停止文件下载 n4* hQi+d
public void siteStop() Av3qoH)[<
{ ?=C?3R
bStop = true; <[N"W82p
for(int i=0;i<nStartPos.length;i++) {i}z|'!
fileSplitterFetch.splitterStop(); R['k&jyi
JYQ.Y!X1O
y:\ ^[y IQ
} zQ[g*
} C9?R*2L>
//负责部分文件的抓取 !%pY)69gv
**FileSplitterFetch.java Ai99:J2k
*/ Q2 tM~
package NetFox; c_oI?D9
[;IW'cXNq
jSY&P/[xb
import java.io.*; =v(MdjwFl
import java.net.*; ^4D7sS;~3
.'+*>y!
m@qM|%(0x
public class FileSplitterFetch extends Thread { Qf?5"=:#
0H|U9
ve#*qz Y
String sURL; //File URL =e<;B_~.
long nStartPos; //File Snippet Start Position y1zNF$<q
long nEndPos; //File Snippet End Position m%mA0r
int nThreadID; //Thread's ID ?B&Z x-krd
boolean bDownOver = false; //Downing is over BC/oh+FW3
boolean bStop = false; //Stop identical %FN3/iM
FileAccessI fileAccessI = null; //File Access interface t6zc$0-j"
*""JE'wG
\M@9#bd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CTqAhL 4}
{ Y+ZQN>
this.sURL = sURL; p^=>N9
this.nStartPos = nStart; n9qO;X4&
this.nEndPos = nEnd; #Kr\"o1]
nThreadID = id; \ow3_^Bk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u9d4zR
} bo;;\>k
IV"OzQONx
^>?E1J3u
public void run() J2c.J/o
{ /U|>
while(nStartPos < nEndPos && !bStop) vY+{zGF
{ urJ>dw?FI
O{0TS^
~j1.;WId[
try{ Afpj*o
URL url = new URL(sURL); i&|fGX?-I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y Mes314"
httpConnection.setRequestProperty("User-Agent","NetFox"); +3@d]JfMh
String sProperty = "bytes="+nStartPos+"-"; yQ^k%hHa
httpConnection.setRequestProperty("RANGE",sProperty); I=N;F6
Utility.log(sProperty); bu;3Ib3\
,&wTUS\
D][e uB
InputStream input = httpConnection.getInputStream(); M7$ h
//logResponseHead(httpConnection); Mn<G9KR
|*~=w J_
Jd].e=]pN
byte[] b = new byte[1024]; kG =nDy
int nRead; rZ.,\ X_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kh11Y1Q0d
{ qbrf;`
nStartPos += fileAccessI.write(b,0,nRead); yMdAe>@
//if(nThreadID == 1) 6usy0g D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lq4vX^S
} Lk%u(duU^
U#o5(mK
?dWfupO{
Utility.log("Thread " + nThreadID + " is over!"); $On
bDownOver = true; /}_OCuJJ,
//nPos = fileAccessI.write (b,0,nRead); %?o@YwBo^E
} fS( )F*J
catch(Exception e){e.printStackTrace ();} ?,dbrQ
} @;T>*_Yhn
} c"vF i~Db
3f 1@<7*
&VY(W{\eY
//打印回应的头信息 (-V=&F_
public void logResponseHead(HttpURLConnection con) oiG@_YtR
{ ~:65e 8K
for(int i=1;;i++) ?J;*
{ %s]l^RZ
String header=con.getHeaderFieldKey(i); os\"(*dix
if(header!=null) c0lVt)pr/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c|f)k:Q
Utility.log(header+" : "+con.getHeaderField(header)); ##%R|P3
else ,zCrix 3
break; wm3fd7T
} njz:7]>e
} Tk9/1C{8
j( *;W}*^
z0@)@4z!
public void splitterStop() In-W,
{ V;b^b5yZ>
bStop = true; _g%Wx?K9
} T>"GH M
Ek!$Ary
4r@dV%:%<
} p[Z'Fl
nN|zEw]
?WD|a(
/* e/;1<5tfj
**FileAccess.java 4o:
*//文件访问(定位，写) ^1&xt(G
package NetFox; 8}Pd- .se
import java.io.*; fk(l.A$
4:!KtpR[O
vt;<+"eps
public class FileAccessI implements Serializable{ ^k&T?uU
d|,,,+fS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jg ~;s
RandomAccessFile oSavedFile; 3I)!.N[m
long nPos; 8]DN]\\o
mp_(ke
|"[[.Adw9"
public FileAccessI() throws IOException |51z&dG
{ )^&,[Q=i
this("",0); M2[ywab
} ~I0I#_$'P
B_u+$Odo
&Wj %`T{
public FileAccessI(String sName,long nPos) throws IOException .x__X3P>\
{ l}>gG[q!
oSavedFile = new RandomAccessFile(sName,"rw"); /2,s-^
this.nPos = nPos; sje}E+{[
oSavedFile.seek(nPos); E%g_O_
} LK8K=AA3P
3r=IO#
cmQLkT"#K
public synchronized int write(byte[] b,int nStart,int nLen) 9R XT
{ /rd6p{F
int n = -1; ~rBeJZ
try{ (7nWv43
oSavedFile.write(b,nStart,nLen); Qtmsk:qm
n = nLen; ~%Y*2i f
} _7SOl.5ZE
catch(IOException e) &`7tX.iMlh
{ (h0i2>K
e.printStackTrace (); s[:e '#^
} -\;x>=#B
e![|-m%
IX eb6j8
return n; thk33ss:
} f"h{se8C
a;p3Me7
LC5NB{b\%>
} A"S{W^iL
%YhZ#>WT
w < p
/* zosJ=$L
**SiteInfoBean.java *Yk3y-
*/ w{[OtGIi3
package NetFox; pCSR^ua>
EEQW$W1@
/}?"O~5M"
public class SiteInfoBean { R1'bB"$
]}/LNO*L"
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private String sSiteURL; //Site's URL Mn(:qQo^&`
private String sFilePath; //Saved File's Path brN:Ypf-e
private String sFileName; //Saved File's Name 4LYeacL B
private int nSplitter; //Count of Splited Downloading File wU_e/+0h
Q7`}4c)
Qcu1&t\C
public SiteInfoBean() Xj.Tg1^K"
{//nSplitter的缺省值为5 hV_eb6aj}P
//default value of nSplitter is 5 #$(F&>pj
this("","","",5); ^{8r(1,
} _yTGv-
' }rUbJo
]zHUF!a*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ysA~Nq@
{ oB8u[!
sSiteURL= sURL; iXtar;%
sFilePath = sPath; B8z3W9
sFileName = sName; ,u|vpN
this.nSplitter = nSpiltter; q4$zsw
ml7]sN(
EBS04]5ul
} e!*d(lHKos
0|8c2{9X,
}6}Gj8Nb
public String getSSiteURL() ~;W]0d4,\
{ AE1!u{
return sSiteURL; y5>859"h
} U3MfEM!x
^G{3x
ny17(Y =
public void setSSiteURL(String value) xd\k;nq
{ w> `3{MTQ
sSiteURL = value; j{EN %
} uWR\#D'
$trvNbco
]ERPWW;^
public String getSFilePath() Ia:n<sZU
{ $x]'6
return sFilePath; [;II2[5 ,
} ]V J$;v'{[
3dNOXk,#
9RwD_`D(MN
public void setSFilePath(String value) HF}%Ow
{ +`l>_u'
sFilePath = value; uiDK&@RS
} 9vT@ mqKu
^2OBc
hZ!N8nWwNR
public String getSFileName() >5)E\4r-
{ A!&p,KfT5+
return sFileName; 2MmqGB}YcW
} hZ-No
UOH2I+@V
5+dQGcE@
public void setSFileName(String value) V*SKWP
{ +=hiLfnE
sFileName = value; &!#,p{}ccU
} roYoxF;\
}|MGYS)
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public int getNSplitter() FR_R"p
{ ?B@(W(I
return nSplitter; Z8+{ -
} ^Fgmwa'
ZWaHG_ U)
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public void setNSplitter(int nCount) =Y>_b 2
{ ^il'Q_-{
nSplitter = nCount; ]&w>p#_C
} si,fs%D&
} 3{ i'8
ZP5.?A-=C
v|`f8M2
/* R"#DR^.;
**Utility.java ENm\1
*/ :%Na-j9hV)
package NetFox; >t')ZSjRs
:<f7;.
K?:rrd=7q
public class Utility { ST1PSuC~
_x_om#~n
EaGh`*"w(7
public Utility() c*$&MCh
{ bz'V50
jdiFb~5R
B'>(kZYMs
} Q9=vgOW+
),y{.n:wm
//线程睡眠 #`)zD"CO
public static void sleep(int nSecond) W-zD1q~0?
{ _P.+[RS@
try{ p*E_Po
Thread.sleep(nSecond); ) D:M_T2
} S83wAr9T
catch(Exception e) ;g$s`l/ 4
{ thcj_BZ8
e.printStackTrace (); Q.Uyl:^PxU
} lR_ 4iyqb
} O?|opD
q\*",xZxwz
//日志 DJP)V8]!B
public static void log(String sMsg) ~.7r
{ Y}%=:Yt
System.err.println(sMsg); Q`}1 B
} YqwDvJWX
gE'b.04Y9i
.w2X24Mmb
public static void log(int sMsg) _!6~o>
{ OnFx8r:q@%
System.err.println(sMsg); V}(snG,
} pH5"g"e1
} vk:@rOpl
rCqcl
M0g!"0?
/* ~E&drl\
**TestMethod.java fM,U|
*/ /Hb'3,jN
package NetFox; g-j`Ex%
hyv*+FV;
X+"8yZz3?
public class TestMethod { )$V}tr!
\ a18Hp|%
Ag QR"Nu6
public TestMethod() sI4Ql0[
{ ///xx/weblogic60b2_win.exe zbn0)JO
try{ !^BXai/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L9[? qFp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]X/1u"
SiteFileFetch fileFetch = new SiteFileFetch(bean); $[txZN
fileFetch.start(); Ld6j;ZJ';
} uSp=,2)
catch(Exception e){e.printStackTrace ();} gK7j~.bb"
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+~mBo+ ,
} l}B,SkP^
2ijw g~_@
H~x,\|l#
public static void main(String[] args) qYZ\<h^
{ j;@7V4'
new TestMethod(); l<0BMwS8
} LQ pUyqR
} *+TIF"|1
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