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)); ,n2"N5{jw
} "A> _U<Y
for(int i=0;i<nEndPos.length-1;i++) \ B'AXv6
{ G+&pq
nEndPos = nStartPos[i+1]; e$Mvl=NYp\
} \EXa 9X2
nEndPos[nEndPos.length-1] = nFileLength; qLPuKIF
} V%B~ q`4
} -Iis/Xw:
y\})C-&
gT(8.<h8
//启动子线程 -Jf}3$Ra
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1aZGt2;
for(int i=0;i<nStartPos.length;i++) D"2bgw
{ w"37sv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H>Ucmd;ay
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dUUg}/
nStartPos,nEndPos,i); ' &3,qT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wD:2sri
fileSplitterFetch.start(); :cf#Tpq"
} r@}8TE*|P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FU(2,Vl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gLRDd~H
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Omi/sKFMi
nEndPos = " + nFileLength); I9dX\w}
// fileSplitterFetch[nPos.length-1].start(); =ym<yI<
vOLa.%X]h
5,4m_fBoW
//等待子线程结束 {9@u:(<X9
//int count = 0; <xe_t=N
//是否结束while循环 Cg|\UKfy$
boolean breakWhile = false; LIrebz
06M?ecN
JL>frS3M
while(!bStop) ddN G:
{ :>/6:c?atG
write_nPos(); CYlS8j
Utility.sleep(500); LJom+PxF$x
breakWhile = true; *<[zG7+&[
)TEm1\
/::Y &&$f
for(int i=0;i<nStartPos.length;i++) 4U16'd
{ WEJ-K<A(
if(!fileSplitterFetch.bDownOver) !iq|sXs
{ #G_'5{V
breakWhile = false; T|0+o+i
break; 8.>himL
} ]G D` f
} \ @[Q3.VX
if(breakWhile) |fW_9={1kQ
break; kv6nVlI)B
.wmqaLd%
&YcOmI/MM
//count++; N:okt)q:%
//if(count>4) cRuN;
// siteStop(); zWv0y8[d
} yn"4qC#Z
J .VZD
O;5lF
System.err.println("文件下载结束！"); ?;H}5>^8P
} Pjn{3/*wi
catch(Exception e){e.printStackTrace ();} j@w1S[vt
} ,<'>jaC
Br15S};Ce
z{FFTb^B
//获得文件长度 2Y<]X7Ch:
public long getFileSize() FE]UqB
{ )0]U"Nf ho
int nFileLength = -1; 1D38T
try{ Dx`-h#
URL url = new URL(siteInfoBean.getSSiteURL()); 0AdxV?6z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Fi;H
httpConnection.setRequestProperty("User-Agent","NetFox"); ^8A[ ^cgq
!%D';wQ,/
vj344B
int responseCode=httpConnection.getResponseCode(); VX82n,'=t
if(responseCode>=400) TVx `&C+
{ I{r*Y9
processErrorCode(responseCode); N>,`TsUwW
return -2; //-2 represent access is error _Gf-s51s
} M0~%[nX
!_QT{H
F>3 o0ke}
String sHeader; k& +gkJm
E1tCY.N{
dq`{fqGl
for(int i=1;;i++) k].swvIi
{ D7T|K :F)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E>f{j:M
//Utility.log(in.readLine()); *coUHbP9>
sHeader=httpConnection.getHeaderFieldKey(i); AWYlhH4c?t
if(sHeader!=null) G}^=(,jl
{ P"l'? `
if(sHeader.equals("Content-Length")) 1+WVh7gF
{ i>]PW|]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `}KxzD
break; 1kw*Q:
} )dqNN tS
} 0 p?AL=
else fK+ 5
break; pjX=:K|
} Eu:/U*j
} C}pm>(F~
catch(IOException e){e.printStackTrace ();} ZJQFn
catch(Exception e){e.printStackTrace ();} 1}c'UEr%)
gwQMy$
iB"ji4[z
Utility.log(nFileLength); )\ceanS
7=9>yba)^
Su"Z3gm5Kw
return nFileLength; 9Dgs A`{$
} Ul9^"o
K%+4M#jj5
Q}OloA(+
//保存下载信息（文件指针位置） op5`#{
private void write_nPos() 8cG`We8l&
{ q(:L8nKT]
try{ ~F@n `!c
output = new DataOutputStream(new FileOutputStream(tmpFile)); .pQ5lK(R
output.writeInt(nStartPos.length); cS7\,/4S
for(int i=0;i<nStartPos.length;i++) kj[boxN
{ _1qR1<V
// output.writeLong(nPos); 3MFTP5~
output.writeLong(fileSplitterFetch.nStartPos); @R50M (@W
output.writeLong(fileSplitterFetch.nEndPos); !?0C(VL(:
} ;'8Wl
output.close(); N+B!AK0.
} 'JJKnE zQ
catch(IOException e){e.printStackTrace ();} ~{tO8 ]
catch(Exception e){e.printStackTrace ();} |xcC'1WU
} Qd kus214
QfAmGDaYQ
v9-4yZU^WR
//读取保存的下载信息（文件指针位置） IPK1g3Z
private void read_nPos() xh$yXP0/
{ vm_]X{80;
try{ t_w\k_ T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -43>?m/a
int nCount = input.readInt(); B I)@n:p
nStartPos = new long[nCount]; U364'O8_
nEndPos = new long[nCount]; m^!j)\sM5
for(int i=0;i<nStartPos.length;i++) T@U,<[,
{ BJWlx*U]
nStartPos = input.readLong(); }7 +%k/
nEndPos = input.readLong(); /go[}X5QR[
} qe{;EH*
input.close(); 8IRKCuV
} Q|h$D~
catch(IOException e){e.printStackTrace ();} zpT^:Ag
catch(Exception e){e.printStackTrace ();} n19A>,m
} GHd1?$
^ExuIe
$V!.z%Vgf
private void processErrorCode(int nErrorCode) XV]xym~
{ 8+}rm6Y+
System.err.println("Error Code : " + nErrorCode); <3BGW?=WP
} \WFcb\..
XZARy:+bc
bRy(`
//停止文件下载 q%])dZ!lE
public void siteStop() #<b\BqYG
{ 5)T[ha77u
bStop = true; [;Lgbgt3f
for(int i=0;i<nStartPos.length;i++) V<S6a
fileSplitterFetch.splitterStop(); G&^8)S@1
<i</pA
!>> A@3
} 3=sBe HL
} (~N?kh:
//负责部分文件的抓取 S,6/X.QBv
**FileSplitterFetch.java YZ+G7D>
*/ AZc=Bbh
package NetFox; trwQ@7
EA>.SSs!
>9A18xC
import java.io.*; C{85#`z`
import java.net.*; G`O*AQ}[
rP7 QW)NF
>P~*@>e
public class FileSplitterFetch extends Thread { *{#C;"
0H>gMXWE]
zu{K"7Bx
String sURL; //File URL 1gkpK`u(B
long nStartPos; //File Snippet Start Position 1m"WrTen
long nEndPos; //File Snippet End Position g{6jN
int nThreadID; //Thread's ID (JlPe)Q5
boolean bDownOver = false; //Downing is over ]VKQm(,0
boolean bStop = false; //Stop identical Ut\:jV=f
FileAccessI fileAccessI = null; //File Access interface Gm:s;w-;v
U52V1b
z~vcwiYAP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GWuKDq
{ FNH)wk
this.sURL = sURL; nL=+`aq_
this.nStartPos = nStart; Yft [)id
this.nEndPos = nEnd; d=^QK{8
nThreadID = id; Pb?vi<ug+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :FI D,
} ao9#E"BfM
Eej Lso#\
]#f%Dku.m
public void run() lL:!d.{
{ 4E5;wH
while(nStartPos < nEndPos && !bStop) Rkg8
{ NJsaTBT
@a@}xgn{
_xCYh|DlQ|
try{ a($7J6]M
URL url = new URL(sURL); (@XQ]S}L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Tph^o^
httpConnection.setRequestProperty("User-Agent","NetFox"); ,b!D8{W"N
String sProperty = "bytes="+nStartPos+"-"; V9$T=[
httpConnection.setRequestProperty("RANGE",sProperty); |;~=^a3?q
Utility.log(sProperty); i8e*9;4@
T{Xd>
pZ|{p{_j
InputStream input = httpConnection.getInputStream(); o{#aF=`{
//logResponseHead(httpConnection); xtP:Q9!N
zw15r" R
) dk|S\
byte[] b = new byte[1024]; 9!X3Cv|+L
int nRead; uOzoE_i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B_ict)}ld
{ !xck ~EAS
nStartPos += fileAccessI.write(b,0,nRead); Z[*unIk
//if(nThreadID == 1) p=nbsS~":
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f4P({V
} ^zV_vB)n
C\5G43`
QyVAs;
Utility.log("Thread " + nThreadID + " is over!"); )S+fc=
bDownOver = true; ]m1p<*0I$
//nPos = fileAccessI.write (b,0,nRead); SgxrU&::
} Fdhgm{Y2s
catch(Exception e){e.printStackTrace ();} R`<2DC>h9
} 7BU7sQjs
} kVWcf-f
E& 6I`8
z7IJSj1gQI
//打印回应的头信息 xD&n'M]
public void logResponseHead(HttpURLConnection con) ;G8H'gM07
{ kHhp;<
for(int i=1;;i++) Ny7*MZ-
{ T>% 5<P
String header=con.getHeaderFieldKey(i); hJxL|5Uo
if(header!=null) MwRLv,&"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *h0D,O"0
Utility.log(header+" : "+con.getHeaderField(header)); RN-gZ{AW
else .8s-)I
break; f#:3TJV
} %f&Y=
} HBe*wkPd
Sk+XBX(}
axUj3J>
public void splitterStop() 1-E6ACq
{ r9{@e^Em
bStop = true; 7OmT^jV2
} I{dy,\p
j36YIz$a
Z}!'fX."
} x@q.u3o9
ZS=H1
k)7i^1U
/* 7oF3^K'S
**FileAccess.java d*{Cv2A.
*//文件访问(定位，写) <!RkkU& 6
package NetFox; 7uc\AhOk6
import java.io.*; ~wuCa!!A
EQlb:;j
N8Rq7i3F?a
public class FileAccessI implements Serializable{ }p6]az3
Lp:VU-S
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8WQ#)
RandomAccessFile oSavedFile; #[9UCX^=
long nPos; lfDd%.:q4S
_1E c54D
F_:zR,P%#
public FileAccessI() throws IOException X,VI5$
{ nm#23@uZ4K
this("",0); WRu(F54Sk
} `ZEFH7P
M}[Q2v\
8d5#vm
public FileAccessI(String sName,long nPos) throws IOException ,e'm@d$Q*
{ \0 h>!u
oSavedFile = new RandomAccessFile(sName,"rw"); CA igV$
this.nPos = nPos; 2o<*rH
oSavedFile.seek(nPos); K_L7a>Fr
} lfM vNv
KDEyVYO:
n~yHt/T
public synchronized int write(byte[] b,int nStart,int nLen) cy,6^d
{ n(Nu
int n = -1; :1qLRr
try{ sG#Os
oSavedFile.write(b,nStart,nLen); ?1\I/'E9
n = nLen; 3v_j*wy
} /Q@4HV
catch(IOException e) eG(YORkR
{ /~'C!so[v
e.printStackTrace (); r~T!$Tb
} LAk .f
"W6cQsi
?9{^gW4|
return n; el5Pe{j'
} ^V;r
cwvJH&%0
5lHt~hB\
} a({Rb?b
wwdmz;0S
P<R^eLZ<&
/* DI8I'c-P
**SiteInfoBean.java Wtu-g**KN
*/ 9{fP.ifdv7
package NetFox; Ao?b1VYy/
@xo8"kl
'L O3[G{
public class SiteInfoBean { -S]ercar
`?=3[
A nl1+
private String sSiteURL; //Site's URL ]*a(^*}A%
private String sFilePath; //Saved File's Path 0O'M^[=d.8
private String sFileName; //Saved File's Name #0r^<Yn
private int nSplitter; //Count of Splited Downloading File {'zS8
7#"NKxb
:|5 m"X\
public SiteInfoBean() cu}(\a
{//nSplitter的缺省值为5 UUWRC1EtI
//default value of nSplitter is 5 >b\|%=(x!*
this("","","",5); I52nQCXi
} 0);5cbV7i
-<x%
o0No"8DnjH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) l,Q`;v5|
{ 31^/9lb
sSiteURL= sURL; fIpS P@$<
sFilePath = sPath; ~_;.ZZ-H]
sFileName = sName; GtmoFSZ
this.nSplitter = nSpiltter; `/m]K~~
]vcT2lr]
/[Fk>Vhp
} ^3sv2wh^|8
?pJ2"/K
Ma?uB8o+~
public String getSSiteURL() $9\8?gS
{ HHw&BNQG
return sSiteURL; gLt6u|0q
} hO> q|+mC
~ a2A"#f
oNXYBeu+
public void setSSiteURL(String value) Iw[zN[oz
{ 9-j-nx @)
sSiteURL = value; 0aR.ct%
} .6[8$8c
.sit5BX
nl2Lqu1
public String getSFilePath() +~F>:v?Rh
{ #"A`:bjG
return sFilePath; 5);"()g32
} IW nG@!
iDDq<a.A
P2ySjgd
public void setSFilePath(String value) vRaxB
{ 4 w*m]D{
sFilePath = value; }L Q%%
} B_Gcz5
fGj66rMGw
Se[=$W
public String getSFileName() [%LGiCU]
{ `@\FpV[|P
return sFileName; m-C#~Cp36
} !4^Lv{1QZ
Ye|gW=FUR
0?FJ~pu
public void setSFileName(String value) G@D8[
{ 8}[<3K%*g
sFileName = value; &VU^d3gv~
} ok,O/|E}?
}@$CS5w
>nehyo:#
public int getNSplitter() ]c_lNHssmq
{ ~,F]~|U7l
return nSplitter; #bGYHN
} #r>)A
2PPb
C4X3;l Z%S
public void setNSplitter(int nCount) +{6:]
{ 1l}Am>}
nSplitter = nCount; VZamR}x
} dXn$XGF%R
} -k>k<bDAI
r.LOj6c
3:sc%IDP
/* 1A;,"8kBd
**Utility.java XH0Vs.w
*/ c;29GHs2
package NetFox; o|84yT!~
A0.xPru1p
7Fa<m]k
public class Utility { GdScYAC
_{LmJ?!
7]5+%[Dg!
public Utility() ~PpU'[
{ !:vQg+S
b+AxTe("
4u2_xbT
} #EKnjh=Uq
e=jtF"&
//线程睡眠 qoph#\
public static void sleep(int nSecond) fk2Uxg=[
{ C_[ d
try{ ?<0'h{zNy
Thread.sleep(nSecond); 3M^`6W[;
} ze+S_{
catch(Exception e) #\="^z6
{ lzFg(Ds!f
e.printStackTrace (); }]=A:*jD
} [;toumv
} (Ze\<Y#cv
`"~X1;
//日志 7|J&fc5BP
public static void log(String sMsg) i7\>uni
{ a(JtGjTf&
System.err.println(sMsg); ~d3BVKP5
} Z>NA 9:
F')E)tV
E}36
public static void log(int sMsg) |~Awm"
{ u91
System.err.println(sMsg); Jx&+e,OST
} x41t=E](
} "1P2`Ep;
_ -ec(w~/
(d <pxx
/* -%VFC^'5
**TestMethod.java k]TJL9Q
*/ tJGPkeA
package NetFox; N7s9"i
1mEW]z
O1]XoUH<
public class TestMethod { 9 771D
aO<H!hK
cwUor}<|
public TestMethod() !VfVpi+-
{ ///xx/weblogic60b2_win.exe )pey7-P7g5
try{ `AdHyE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2NL|_W/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;ov}%t>UD
SiteFileFetch fileFetch = new SiteFileFetch(bean); pAEJ=Te
fileFetch.start(); ~3Z(0gujD
} YWq{?'AaR
catch(Exception e){e.printStackTrace ();} giN(wPgYP
sg]g;U
@[rlwwG,
} [9p@uRE
mL,{ZL ^
l4^8$@;s
public static void main(String[] args) ,6U=F#z
{ hn/SS
new TestMethod(); Qbj:^{`>(
} zWdz9;=_
} m]\d9%-AT&
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