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)); >7|37a
} kL-+V)Kl
for(int i=0;i<nEndPos.length-1;i++) 2+.m44>Ti
{ =ZQIpc
nEndPos = nStartPos[i+1]; ?S_S.Bd
} .1@5*xQ5O
nEndPos[nEndPos.length-1] = nFileLength; Z&%61jGK
} ;3!TOY"j;e
} {f)p|)
seq$]
:MVD83?4
//启动子线程 a'Z"Yz^Eo
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; OQq7|dZu
for(int i=0;i<nStartPos.length;i++) SO)??kQ{U
{ eXYR/j<8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L`\ILJz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ll#PCgIm
nStartPos,nEndPos,i); iAN#TCwLT7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;8@A7`^
fileSplitterFetch.start(); ,oCr6 ]
} F~B8XUa3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ah,Zm4:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (.c?)_G,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yVL~SH|
nEndPos = " + nFileLength); #ua#$&p
// fileSplitterFetch[nPos.length-1].start(); ?@nu]~
Gi-tf<
?}y7S]B FI
//等待子线程结束 Ul=`]@]]
//int count = 0; pO^ 6p%
//是否结束while循环 (<ejJPWT
boolean breakWhile = false; U5klVl
R:E`
DeUDZL%/
while(!bStop) T<OLfuV
{ >4Lb+]
write_nPos(); dL"v*3Fy
Utility.sleep(500); ()7=(<x{
breakWhile = true; D526X0
yS?1JWUC>
/4|qfF3
for(int i=0;i<nStartPos.length;i++) Uz0mSfBp
{ G -;Yua2\
if(!fileSplitterFetch.bDownOver) 7(jt:V6V
{ 8S0)_L#S
breakWhile = false; w4OVfTlN
break; MV/JZ;55
} csC3Wm{v
} Z5+0?X0i
if(breakWhile) u@o3p*bQ
break; fROhn}<**[
aAX 8m
t~Uqsa>n@'
//count++; +h =lAHn&
//if(count>4) 8Hhe&B
// siteStop(); $oNkE
} !v^D j']
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{ "/@,!9rJ
System.err.println("文件下载结束！"); ;{>z\6N
} Nk7Q
catch(Exception e){e.printStackTrace ();} P"- ,^?6
} k8h$#@^
OvFZ&S[
O6`@'N>6P
//获得文件长度 X 6>Pq
public long getFileSize() <_NF
{ $rdA0%;
int nFileLength = -1; `Z{7Ut^)
try{ TPkm~>zD.
URL url = new URL(siteInfoBean.getSSiteURL()); xT@\FwPr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nI6`/
httpConnection.setRequestProperty("User-Agent","NetFox"); |h.he_B+7
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Abj`0\
int responseCode=httpConnection.getResponseCode(); t+vn.X+&
if(responseCode>=400) q* m%Fv
{ t?/#:J*_7
processErrorCode(responseCode); !D1F4v[c=
return -2; //-2 represent access is error tUtl>>6Iu
} u~G,=n
ZJ!/49c*>
kcQ |Zg
String sHeader; Jl}$)'
p<$z!|7m
8(BLS{-"<
for(int i=1;;i++) Q<"zpwHR
{ f$P pFSY4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g6N{Z e Wg
//Utility.log(in.readLine()); vXyaOZ
sHeader=httpConnection.getHeaderFieldKey(i); A }dl@
if(sHeader!=null) ;'nu9FU*O
{ {dA#r>z\1
if(sHeader.equals("Content-Length")) 0|d%@
{ }lWEbQ)(!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JeiW z1t
break; ?p/i}28=y
} B&tl6?7h
} $ZE OE8.\
else ]92@&J0w
break; 27;*6/>,
} &!~q#w1W-5
} e`Yx]3;u(
catch(IOException e){e.printStackTrace ();} \5J/?
catch(Exception e){e.printStackTrace ();} aG,N>0k8
NK d8XQ=%
#A?U_32z/2
Utility.log(nFileLength); a?@j`@]ZR~
*!Xhy87%Z)
iX~V(~v
return nFileLength; YT#"HYO
} [_${N,1
r]2}S=[
T#T!a0
//保存下载信息（文件指针位置） TC ^EyjD
private void write_nPos() qdOaibH_
{ P E.^!j
try{ .4U::j}
output = new DataOutputStream(new FileOutputStream(tmpFile)); #VD[\#
output.writeInt(nStartPos.length); E_-CsL%
for(int i=0;i<nStartPos.length;i++) KbSIKj
{ ]_j{b)t
// output.writeLong(nPos); J8(v65
output.writeLong(fileSplitterFetch.nStartPos); U2!9Tl9".
output.writeLong(fileSplitterFetch.nEndPos); {ImZ><xe/
} wz;IKdk[
output.close(); Dk8" H>*
} .|cQ0:B[
catch(IOException e){e.printStackTrace ();} 7+@:wX\
catch(Exception e){e.printStackTrace ();} ^cd+W?
} ~^Gk7
@TsOc0?-
}F**!%4d
//读取保存的下载信息（文件指针位置） _aq3G9C_
private void read_nPos() _v<EFal
{ Pr/K5aJeg
try{ -cEjB%Neo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )mJl-u[0+
int nCount = input.readInt(); 4mUQVzV
nStartPos = new long[nCount]; YG<?|AS/
nEndPos = new long[nCount]; l[.RnM[v
for(int i=0;i<nStartPos.length;i++) lY0^Z
{ i9uJ%nd:
nStartPos = input.readLong(); T[L
nEndPos = input.readLong(); HBeOK
} f0}+8JW5h
input.close(); zR">'bM:
} 9 *Q/3|
catch(IOException e){e.printStackTrace ();} b4i=eI8
catch(Exception e){e.printStackTrace ();} ^#p Su
} *r$(lf
StA5h+[m
$ ^m_M.1
private void processErrorCode(int nErrorCode) JT,8/o
{ \Ua"gS2L
System.err.println("Error Code : " + nErrorCode); 4mPCAA7
} ^HQg$}=
rl[&s\[
}`M[%]MNc
//停止文件下载 9psD"=/"
public void siteStop() 6O!&!
{ 8E ^yHd4Y
bStop = true; p'ukV(B
for(int i=0;i<nStartPos.length;i++) gVl%:Ra%
fileSplitterFetch.splitterStop(); G)M9to
MW6d-
S2h?Q$e3
} D`2Iy.|!
} PJsiT4<
//负责部分文件的抓取 NAlYfbp
**FileSplitterFetch.java +t})tDPXw
*/ a3sXl+$D@
package NetFox; a>G|t5w
6m|j "m
-!k"*P
import java.io.*; vn9_tL&
import java.net.*; hj4Kv
u+~Ta
p{[Ol
public class FileSplitterFetch extends Thread { *O+G}_}
,?P@ :S<8
%70sS].@
String sURL; //File URL )E'iC
long nStartPos; //File Snippet Start Position g,@0 ;uVq
long nEndPos; //File Snippet End Position $RfM}!7?
int nThreadID; //Thread's ID XL1v&'HLV
boolean bDownOver = false; //Downing is over %c*azo.
boolean bStop = false; //Stop identical M`-.0
FileAccessI fileAccessI = null; //File Access interface jqhd<w
m\)z& hv<r
D4?5%s
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M8oI8\6[
{ H~^am
this.sURL = sURL; T&
this.nStartPos = nStart; 51u8.%{4
this.nEndPos = nEnd; !U/iY%NE
nThreadID = id; .;8T*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9#IKb:9k
} al.~[T-O+
w(zlHj
S~.:B2=5K
public void run() }Zu>?U
{ xv4_q-r[
while(nStartPos < nEndPos && !bStop) sk.<|-(o
{ <O>1Y09C/
Po#;SG#Ee
,W;\6"Iwx'
try{ wO;\,zU
URL url = new URL(sURL); :,X,!0pWRp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &9g4/c-?$
httpConnection.setRequestProperty("User-Agent","NetFox"); }SR}ET&z
String sProperty = "bytes="+nStartPos+"-"; `L/kwVl
httpConnection.setRequestProperty("RANGE",sProperty); o}C|N)'
Utility.log(sProperty); DG}} S5
Xt %;]1n
e "5S;
InputStream input = httpConnection.getInputStream(); wu"6Kyu
//logResponseHead(httpConnection); '8R5?9"
wuSp+?{5k
u=JI 1
byte[] b = new byte[1024]; .H {
int nRead; FIG3P))
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) s-!Bpr16o0
{ Av:5v3%
nStartPos += fileAccessI.write(b,0,nRead); {{7%z4l
//if(nThreadID == 1) %]S~PKx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2It$ bz
} (vMC.y5
wg\*FfQn
yJkERiJV
Utility.log("Thread " + nThreadID + " is over!"); 8.3888
bDownOver = true; B#9rqC
//nPos = fileAccessI.write (b,0,nRead); Z[[ou?c
} cLj@+?/
catch(Exception e){e.printStackTrace ();} O:cta/M
} ^|M\vO
} TO7%TW{L
!*_5 B'
v<c~ '?YzO
//打印回应的头信息 Bt[OGa(q
public void logResponseHead(HttpURLConnection con) &(UVS0=Dp,
{ K<'L7>s3lA
for(int i=1;;i++) |-GmWSK_
{ mZDL=p
String header=con.getHeaderFieldKey(i); yNMnByg3?
if(header!=null) *u^N_y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b0|q@!z>
Utility.log(header+" : "+con.getHeaderField(header)); i>#[*.|P
else m`l3@Z
break; ]@)T]
} /*\pm!]._^
} , v,mBYaU
<8nl}^d5
FjYih>
public void splitterStop() %y;E1pva
{ (jv!q@@2C.
bStop = true; '~Uo+<v$w
} 3)ac
N% /if
*vqlY[2Ax
} `oQ)qa_
V~ph1Boz2
}GX[N\$N
/* SA@MJ>Z
**FileAccess.java 02OL-bv}HS
*//文件访问(定位，写) __<u!;f
package NetFox; 4X,fb`
import java.io.*; `\LhEnIwu
<;}jf*A
7A'd55I4
public class FileAccessI implements Serializable{ rV.04m,
JbN@AX:%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~"F83+RDe
RandomAccessFile oSavedFile; CMn&1
long nPos; 2]W"sT[
Cj^:8 ?%
Gu} `X23
public FileAccessI() throws IOException `|@#~
{ A;VjMfoB
this("",0); &Ohm]g8{2
} FRa@TN/Ic
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rrBu6\D
public FileAccessI(String sName,long nPos) throws IOException :l<)p;\
{ r_/=iYYJ
oSavedFile = new RandomAccessFile(sName,"rw"); _hT-5)1r
this.nPos = nPos; -+fbK/
oSavedFile.seek(nPos); ]l\'1-/
} #LRN@?P
~xI1@^r
M =Pn8<h~
public synchronized int write(byte[] b,int nStart,int nLen) \z"0lAv"
{ $U=E7JO
int n = -1; ZNb;24
try{ v"'Co6fw
oSavedFile.write(b,nStart,nLen); ,'[&" Eg
n = nLen; :.5l9Ci4
} `tZu~ n
catch(IOException e) bH+x `]{A
{ +76{S_CZ
e.printStackTrace (); ds@X%L;_
} g=w,*68vuy
A$*#n8,
O%RkU?ME
return n; jSa9UD
} TS0x8,'$q
0].x8{~o
0uX"KL]Elf
} sjh>i>t
P(OgT/7A
&6!~Q,;K-
/* z.fh4p
**SiteInfoBean.java %JmRJpCvR
*/ _ 4:@+{
package NetFox; QP/6N9/
[^wEKRt&
fBCW/<Z
public class SiteInfoBean { E({+2}=1
u6&<Bv
r(sQI# P
private String sSiteURL; //Site's URL "-aak )7w
private String sFilePath; //Saved File's Path JNhHQvi\
private String sFileName; //Saved File's Name HU[a b
private int nSplitter; //Count of Splited Downloading File RiHOX&-7
Wn;B~
q-c9YOz_
public SiteInfoBean() Z9cg,#(D
{//nSplitter的缺省值为5 [e1kfw
//default value of nSplitter is 5 Hg)5c!F7
this("","","",5); zh5'oE&[yC
} dre@V(\;hQ
X r7pFw
}1]E=!?)&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) a[TR_uR
{ $@m)8T
sSiteURL= sURL; ;8WgbR)ZLU
sFilePath = sPath; DG_tmDT4
sFileName = sName; G9?6qb:
this.nSplitter = nSpiltter; w k1O*_76
!eb}jL
P'o:Vhm_H
} cG|)z<Z
\BB(0Ah+t
M6(oJ*
public String getSSiteURL() Z4S0{:XY
{ eIVCg-l}
return sSiteURL; X8!=Xjl)
} j.C)KwelBS
@V$,H/v:
C+{du^c$
public void setSSiteURL(String value) *We.?"X'].
{ ?O1:-vpZ
sSiteURL = value; )c9]}:W&
} 5`:+NwXS2
U3SF'r8
">b~k;M?
public String getSFilePath() >FtW~J"X
{ -9BKa~ DVQ
return sFilePath; xw60l&s.\L
} z4l O
T';<;6J**
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public void setSFilePath(String value) + -e8MvP
{ }gw `,i
sFilePath = value; gI^);JrTE
} M1._{Jw5
rCcNu
Qxds]5WB/
public String getSFileName() )tQG5.to
{ '&L;y
return sFileName; x'Z<
} bXcDsP$.
bS 'a)
D;bQ"P-m47
public void setSFileName(String value) jRz2l`~7#
{ c"ukV_6~J
sFileName = value; 75Xi%mlE7
} XQEGMaZ
LS:3Dtq
t3 AZS0
public int getNSplitter() bH7[6#y$
{ 33d86H%;
return nSplitter; mT57NP
} iQ= %iou
%N)o*H&
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public void setNSplitter(int nCount) B`Q.<Lqu
{ '8~cf
nSplitter = nCount; o l67x
} $)| l#'r
} W(*:8}m,p
w>I>9O}(`
7^k`:Z
/* +Ux)m4}j
**Utility.java NLDmZra
*/ H[o'j@0
package NetFox; &]~z-0`$!
@+",f]
G'XlsyaWrb
public class Utility { bw#zMU^E
4QWDuLu
9H*$3
public Utility() &fYx0JT
{ s~$kzEtjjU
_>HXQ6Hw
UTQ$sg|7p
} ~p~8T
}~lF Rf
//线程睡眠 OVO0Emv
public static void sleep(int nSecond) [KkLpZG
{ jIMaPT
try{ +MC>?rr_u
Thread.sleep(nSecond); K5(?6hr;
} e,Xvt5
catch(Exception e) uR"srn;^
{ puS'9Lpp
e.printStackTrace (); ]I"oS?
} p#.B Fy
} |0(Z)s,
b:7;zOtF
//日志 i;^ e6A>
public static void log(String sMsg) LBtVK, ?
{ daBu<0\
System.err.println(sMsg); 9\*xK%T+
} CogLo&.
=mCUuY#
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public static void log(int sMsg) y]=v+Q*+
{ ~az6n)
System.err.println(sMsg); (c(c MC'
} Y',s|M1})\
} UuxWP\~2
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b@N|sXt&C
/* K&"Yv~h
**TestMethod.java `Oys&]vb
*/ 1W-t})!a
package NetFox; cWgiFv
'9GHmtdO,
kgK7 T
public class TestMethod { }jTEgog
Js qze'BGY
YP~d1BWvf
public TestMethod() -$;H_B+.
{ ///xx/weblogic60b2_win.exe C 0*k@kGy
try{ 1oo'\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wpY%"x#-+=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g=pz&cz;>\
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8x'rNb
fileFetch.start(); df#DKV:
} pw:<a2.
catch(Exception e){e.printStackTrace ();} yyk[oH-Q
(|ga#%iI
^`YSl*:
} r0QjCFSF=
FqsG#6|x
3z: rUhA
public static void main(String[] args) qYIBP?`g
{ Pf)<6?T
new TestMethod(); VYf$0oo\4
} U_!"&O5lr
} ?TE#4}p|
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