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)); u:FFZ
} ~-.^eT kP
for(int i=0;i<nEndPos.length-1;i++) +~~&FO2
{ D)*OQLHW
nEndPos = nStartPos[i+1]; ]J%p&y+6
} @&G< Np`
nEndPos[nEndPos.length-1] = nFileLength; 6YCFSvA#/
} k-uwK-B}v+
} rIg5Wcd
o :tz_5
Xob,jo}a
//启动子线程 KNw{\Pz~w
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @Ht7^rz+S
for(int i=0;i<nStartPos.length;i++) :J{| /"==
{ H^<LnYZ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 609_ZW;)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X>`5YdT~+
nStartPos,nEndPos,i); :jc ?T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )GpH5N'EI
fileSplitterFetch.start(); ^*fZ
} xc HG5bg|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ojA i2uz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); pDg_^|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8'Y7lOXS
nEndPos = " + nFileLength); 8 FqhSzw
// fileSplitterFetch[nPos.length-1].start(); 1sT%g}w@|
foOwJ}JU
gPu0j4&-
//等待子线程结束 JXBTd=r_oM
//int count = 0; #cRw0bn:
//是否结束while循环 7oK7f=*Q
boolean breakWhile = false; lW!}OzE(m
)O~V3a
\z4I'"MC.9
while(!bStop) !7KSNwGu
{ GkT:7`|C
write_nPos(); ~fDMzOd
Utility.sleep(500); }zkMo?
breakWhile = true; *yx&4)Or
HZHzjrx
M^E\L C
for(int i=0;i<nStartPos.length;i++) GT)63|
{ wLDWD,"K
if(!fileSplitterFetch.bDownOver) bJz}\[z
{ O"<W<l7Q
breakWhile = false; -or^mNB_z
break; aNLkkkJg<;
} >pVrY; P[
} opKk#40
if(breakWhile) (np %urx!
break; D]s8w
x'.OLXx>
z`^DQ8+\j
//count++; z DP
//if(count>4) .)zX<~,
// siteStop(); Wxi|(}
} 4K(AXk
z/,qQVv=}4
7HpfHqJ7
System.err.println("文件下载结束！"); =ca<..yh[d
} WI?iz-,](
catch(Exception e){e.printStackTrace ();} 7I,/uv?
} F>0[v|LG
UA{tmIC\
h#o3qY
//获得文件长度 ~_z"So'|F_
public long getFileSize() nJvDkh#h1
{ &7{/ x~S{
int nFileLength = -1; I.M@we/bR}
try{ t~luBUF
URL url = new URL(siteInfoBean.getSSiteURL()); %4%$NdU"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [^cflmV
httpConnection.setRequestProperty("User-Agent","NetFox"); 4rmSo^vK
Gl1Qbd0
7.r}98V
int responseCode=httpConnection.getResponseCode(); Aj9Onz,Lg
if(responseCode>=400) : *~}\M*
{ M%3\]&
processErrorCode(responseCode); x}`]9XQ
return -2; //-2 represent access is error qm.30 2
} +EmT+$>J
nj (/It
~4YLPMGKl
String sHeader; GAZw4dz
C^o9::ER
;Jn"^zT
for(int i=1;;i++) 7# /c7
{ C/JeD-JG
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S~8w-lG!
//Utility.log(in.readLine()); &?],uHB?d
sHeader=httpConnection.getHeaderFieldKey(i); $/*6tsR
if(sHeader!=null) Tr^Egw]
{ rcC}4mNe
if(sHeader.equals("Content-Length")) nTJ-1A7EP
{ 3 e19l!B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uG|d7LS,%
break; _?vh#6F
} sg.8Sd"]7
} QW5S=7
else \k#|[d5W
break; an4^(SY
} ,~R`@5+
} BVKr 2v
catch(IOException e){e.printStackTrace ();} "5KJ /7q!
catch(Exception e){e.printStackTrace ();} g1je':
t8"*jt
COE,pb17
Utility.log(nFileLength); +s*OZ6i [
%TY;}V59b
fQ\nK H~
return nFileLength; !n=?H1@
} NhI&wl
D# $Fj
BZ]6W/0
//保存下载信息（文件指针位置） {*=+g>RgD
private void write_nPos() UBmD 3|Zo
{ re\@v8w~
try{ LqH<HGMFD
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2k }:)]m
output.writeInt(nStartPos.length); c]#+W@$
for(int i=0;i<nStartPos.length;i++) `5[$8;
{ Q^&oXM'x/i
// output.writeLong(nPos); B?Vr9H7n
output.writeLong(fileSplitterFetch.nStartPos); S~dD;R
output.writeLong(fileSplitterFetch.nEndPos); KjrUTG0oA
} ~wMdk9RQ
output.close(); Bs@!S?
} *4i)aj
catch(IOException e){e.printStackTrace ();} O8;`6r
catch(Exception e){e.printStackTrace ();} A`=;yD
} F{:ZHCm
%idn7STJ}
X5@SLkJ-`
//读取保存的下载信息（文件指针位置） ^w0V{qF{
private void read_nPos() 61Z#;2]
{ (M1HNIM;(
try{ Wc}opp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); DFgr,~
int nCount = input.readInt(); uHBEpqC%
nStartPos = new long[nCount]; ZP@or2No%
nEndPos = new long[nCount]; +d[A'&"
for(int i=0;i<nStartPos.length;i++) *]ROUk@K=
{ bv.DW,l%'
nStartPos = input.readLong(); QT1(= wK3
nEndPos = input.readLong(); ugtzF
} }Yi)r*LI3
input.close(); dmq<vVxC
} tSST.o3
catch(IOException e){e.printStackTrace ();} C~do*rnM^
catch(Exception e){e.printStackTrace ();} p!+7F\
} S?X2MX
dQoZhE
T;cyU9
private void processErrorCode(int nErrorCode) Wq bfZx
{ g/)$-Z)Nu
System.err.println("Error Code : " + nErrorCode); 59?@55
} -#=y
.k{omr&Dy5
|G2hm8 Y
//停止文件下载 \JJ>y
public void siteStop() 4=j,:q
{ :ZP4(}
bStop = true; [x{S ,?6
for(int i=0;i<nStartPos.length;i++) ]gN]Cw\L
fileSplitterFetch.splitterStop(); Z_Gb9
Xx;RH9YYz
'%W'HqVcG1
} U6hT*126
} ]dXHjOpA
//负责部分文件的抓取 rsbdDTy
**FileSplitterFetch.java PGT*4r21
*/ @W\y#5"B
package NetFox; (nhv#&Fd+
br!:g]Vh
OL,3Jh% x
import java.io.*; DzZ)aE
import java.net.*; G2FP|mf,
U Ox$Xwp5&
oDyrf"dl
public class FileSplitterFetch extends Thread { -IBf;"8f
Sm(QgZO[4
9Fe(],AzF
String sURL; //File URL M`W%nvEDE
long nStartPos; //File Snippet Start Position (S:+#v
long nEndPos; //File Snippet End Position traJub
int nThreadID; //Thread's ID oo{5:
boolean bDownOver = false; //Downing is over ~R`Rj*Q2Y
boolean bStop = false; //Stop identical GP"(+5
FileAccessI fileAccessI = null; //File Access interface 7g-#v'.N
btq`[gAF\
fIrl?X']
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aBPaC=g{HO
{ yOn +Y
this.sURL = sURL; `O-LM e
this.nStartPos = nStart; T[w]w
this.nEndPos = nEnd; }$K2h*
nThreadID = id; %-~W|Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \]y4e^FZZ
} uV]4C^k;`[
,hj5.;M
zVLv-U/=d
public void run() ?[4!2T,Ca
{ Ua.7_Em
while(nStartPos < nEndPos && !bStop) ?Rc+H;x=f
{ ,2F4S5F~rC
8^fkY'x
JPS7L}Kv
try{ MCamc
URL url = new URL(sURL); .xtjB8gc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B/IPG~aMEZ
httpConnection.setRequestProperty("User-Agent","NetFox"); F+;{s(wx
String sProperty = "bytes="+nStartPos+"-"; o C]tEXJ
httpConnection.setRequestProperty("RANGE",sProperty); c65_E<5Z
Utility.log(sProperty); GW]E,a
:kycIM]s
=e7,d$i
InputStream input = httpConnection.getInputStream(); <B]\&
//logResponseHead(httpConnection); &Mset^o
N0be=IO5#
zcrLd={
byte[] b = new byte[1024]; {;(X#vK}9
int nRead; LGN,8v<W(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /Kmzi9j+
{ (wmMHo|
nStartPos += fileAccessI.write(b,0,nRead); X\SZ Q[gN
//if(nThreadID == 1) !GkwbHr+p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xCH,d:n=
} L[zg2y
eSZS`(#!(
B;'Dh<J1
Utility.log("Thread " + nThreadID + " is over!"); cH>rS\|Y
bDownOver = true; sQ65QJtt0A
//nPos = fileAccessI.write (b,0,nRead); ; 6Wlu3I
} _m!TUT8o
catch(Exception e){e.printStackTrace ();} |irqv< r
} dw)SF,
} %?^T^P
7@g8nv(p
V/Hjd`n)`i
//打印回应的头信息 |]a=He;
public void logResponseHead(HttpURLConnection con) @Taj++ua
{ &z;;Bx0s
for(int i=1;;i++) [@ ]f@Wd
{ _A*5BAB:h(
String header=con.getHeaderFieldKey(i); jB]tq2i
if(header!=null) %H:uE*WZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qvz2u]IOw
Utility.log(header+" : "+con.getHeaderField(header)); Wjt1NfS&
else `nccRy<l
break; a^qLyF&F
} \Q"o\:IoIT
} [>"bL$tlo*
6JWCB9$4
^o+}3=
public void splitterStop() @R=gJ:&a
{ ^5TSo&qZ
bStop = true; v\*43RL
} hR3lo;'
l-"c-2-!
"J]_B
} nAn/Vu
@Md%gEh;&
H{'<v|I
/* :.['e`
**FileAccess.java ^Yei9bXl
*//文件访问(定位，写) "}UJ~ j).
package NetFox; #Ag-?k
import java.io.*; ko2Kz k
*>!O2c
H4LZNko
public class FileAccessI implements Serializable{ W=M`Bkw{
<}b`2/wP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &eV& +j
RandomAccessFile oSavedFile; W)jO 4,eO
long nPos; SU OuayE
9I8{2]
>N>WOLbb7(
public FileAccessI() throws IOException 9l2,:EQ*
{ &^e%gU8!\
this("",0); #%k!`?^fbK
} *6~ODiB
F)/}Q[o8
JqTkNKi/s
public FileAccessI(String sName,long nPos) throws IOException &P&LjHFK
{ V6"<lK8"
oSavedFile = new RandomAccessFile(sName,"rw"); #|fa/kb~
this.nPos = nPos; vCT5do"C&
oSavedFile.seek(nPos); 4g]Er<-P
} ?Y2ZqI
~vnG^y>%
e2Sm.H '
public synchronized int write(byte[] b,int nStart,int nLen) LtKiJ.j?A
{ t3K7W2bz
int n = -1; D.o|pTZ
try{ }fnp}L
oSavedFile.write(b,nStart,nLen); kf+]bV
n = nLen; MZf$8R
} 6Y6DkFdvrZ
catch(IOException e) {g}!M^|
{ 6V\YYrUz
e.printStackTrace (); S(](C
} $5y%\A
GHeJpS
jr{C/B}
return n; $$~x: iN
} !7!xJ&/V
8;;!2>N
uZ( I|N$
} L+Yn}"gIs
]kq{9b';
Qj~m;F!
/* mdvooJ
**SiteInfoBean.java LziEF-_
*/ ;T~]|#T\6
package NetFox; #}L75
K^`3Bg
j?%^N\9
public class SiteInfoBean { '/U[ ui0{
V{;!vt~
C{!L +]/
private String sSiteURL; //Site's URL /%|JP{
private String sFilePath; //Saved File's Path XVAyuuTg\
private String sFileName; //Saved File's Name 02:]
private int nSplitter; //Count of Splited Downloading File A,i.1U"w8
G$pTTT6#
$,q~q^0
public SiteInfoBean() Htn=h~U`z
{//nSplitter的缺省值为5 ,~8:^*0s
//default value of nSplitter is 5 !/+ZKx("9
this("","","",5); i`/_^Fndyu
} q\ FF)H
ES!$JWK|
/PG+ s6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =3OK3|
{ km2('t7?
sSiteURL= sURL; r#iZ FL3q
sFilePath = sPath; Jm$.$B&I
sFileName = sName; }]_/:KUt
this.nSplitter = nSpiltter; aAZS^S4v
r=P)iE:
l T~RH0L
} r2}u\U4>
=; Gw=m(
Gm;)Om_
public String getSSiteURL() o&P}GcEIw
{ $&/JY
return sSiteURL; n/#zx:d?
} 3ny>5A!;2
}S51yDVG_
tFt56/4
public void setSSiteURL(String value) zY~
{ 5vs~8|aRo
sSiteURL = value; nf&PDv1
} ;q]Jm
C,7d
Z"PPXv-<jY
public String getSFilePath() _@9[c9bO
{ Hs/ aU_
return sFilePath; lo*OmAF
} AE`X4q
i2KN^"v?N
'?dO[iQ$:
public void setSFilePath(String value) D+ mZ7&L
{ 2g~qVT,
sFilePath = value; RUqN,C,m5I
} aTS\NpK&
XWN ra
<WFA3
public String getSFileName() G n"]<8yl~
{ |N_tVE
return sFileName; m3W:\LTTp
} ST$~l7p
)3#gpM
Fw5|_@&k
public void setSFileName(String value) _+PiaJ&'
{ T<(1)N1H`
sFileName = value; #\s*>Z
} .[&0FHnJ5
ap=m5h27
2Ya)I k{
public int getNSplitter() MuXp*s3[
{ O O?e8OU
return nSplitter; FsQeyh>
} ,5oe8\uz
"1O!Ck_n
{$D[l hj
public void setNSplitter(int nCount) O ]o7
{ MB.\G.bV
nSplitter = nCount; &_Kb;UVRj
} j6v|D>I
} -!MrG68
[U9b_`
xi['knUi2-
/* J1OZG6|e
**Utility.java G8=2=/ !
*/ e??tp]PLn
package NetFox; ~C[p}MED
m>yb}+
HVO mM17
public class Utility { n%'M?o]DF
TNe,'S,%
Z9X<W`
public Utility() MzjV>.
{ $ N`V%<W
9U[Gh97Sf
ldp x,
} ql"&E{u?
gc(Gc vdB\
//线程睡眠 AGaM &x=
public static void sleep(int nSecond) ^b|Z<oF
{ 3m3ljy
try{ mGx!{v~i&
Thread.sleep(nSecond); \7b-w81M-
} +B(x:hzY9
catch(Exception e) {UqSq
{ wM.z/r\p
e.printStackTrace (); g4b-~1[S
} tUX4#{)q(j
} ycYT1Sg8
2iOn\ ^]x
//日志 CTawXHM
public static void log(String sMsg) l e+6;'Q
{ :"m~tU3&
System.err.println(sMsg); (w4w
} y8} fj=
WgHl. :R
m$N`Xj
public static void log(int sMsg) m(0sG(A~
{ 4I7B #{
System.err.println(sMsg); \s_lB~"P!3
} rJLn=|uR
} 3V=(P.ATm
J|*Z*m
-s~6FrKy
/* y?=W
**TestMethod.java $ti*I;)h4
*/ U'(Exr[
package NetFox; E/bIq}R6
K:!){a[
Xge]3Ub
public class TestMethod { =BD}+(3
0$=Uhi
?O(@BT
public TestMethod() BR&T,x/d
{ ///xx/weblogic60b2_win.exe ]5(T{
try{ 'I$-h<W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w+A:]SU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LDg"s0n#
SiteFileFetch fileFetch = new SiteFileFetch(bean); .'`7JU#{
fileFetch.start(); RLnsy,
} <//82j+px
catch(Exception e){e.printStackTrace ();} eKRslMa
mL5Nu+#
j /d?c5
} (PVK|Q55y
_N`'R.va
WP(+jL^-
public static void main(String[] args) 'Cki"4%<
{ 'u9,L FO
new TestMethod(); 8H2zMIB
} 3k YVk
} N$'/J-^
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