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)); IAA_Ft
} F]RPM(!5O)
for(int i=0;i<nEndPos.length-1;i++) tk0m[HN@eV
{ 2fdN@iruB
nEndPos = nStartPos[i+1]; `*[Kmb\
} f (C:J[;Z
nEndPos[nEndPos.length-1] = nFileLength; :TVo2Zm[@
} 42e[OG-
} a|TUH+|
<j,I@%
HFB>0<$
//启动子线程 e'~Qe_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Uhu?G0>O
for(int i=0;i<nStartPos.length;i++) 8K^#$,.."
{ xlcCL?qQj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -qpvVLR,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I!b"Rv=Nf-
nStartPos,nEndPos,i); ju:}%'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /1TK+E$
fileSplitterFetch.start(); Dj= {%
} :xg J2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;\"5)S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5%wA"_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9t`yv@.>N
nEndPos = " + nFileLength); ty[%:eG#
// fileSplitterFetch[nPos.length-1].start(); Ud"_[JtGM
<|'ETqP<+
mR2"dq;U
//等待子线程结束 #Br`;hL<T
//int count = 0; ZYB5s~;eB"
//是否结束while循环 Gy+c/gK
boolean breakWhile = false; f2tCB1[D+
+%<kcc3
ZK?V{X{";
while(!bStop) |5(CzXR]
{ Lww&[|k.
write_nPos(); ,aWI&ve6
Utility.sleep(500); %-YWn`yEm
breakWhile = true; DI/d(oFv`
J<NpA(@^
ZT"vVX-)G
for(int i=0;i<nStartPos.length;i++) o^5UHFxTCB
{ g[y&GCKY!=
if(!fileSplitterFetch.bDownOver) Ce//;Op
{ @@a#DjE%/
breakWhile = false; Bd*Ok]
break; ^69(V LK
} TN Z-0
} -~sW@u)O
if(breakWhile) f*V^HfiQb
break; p%Q{Rqc)
e`B!)Sr
x`2dN/wDhf
//count++; 5T"h7^}e
//if(count>4) + S5uxO
// siteStop(); Tq^B>{S"
} (^T}6t3+4
ZCK#=:ln
^-Ks_4
System.err.println("文件下载结束！"); AN,3[Sh
} s!W{ru
catch(Exception e){e.printStackTrace ();} eVj 8u
} o7gZc/?n
.$f0!` t
8\)4waz$
//获得文件长度 3Zz_wr6
public long getFileSize() dr8Q>(ZY
{ %U<lS.i
int nFileLength = -1; a@_n>$LZL
try{ bTx4}>=5l
URL url = new URL(siteInfoBean.getSSiteURL()); A\"4[PXpQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XYV`[,^h&
httpConnection.setRequestProperty("User-Agent","NetFox"); $v8T%'p+
3]NKAPY
1)e[F#|
int responseCode=httpConnection.getResponseCode(); lq1223
if(responseCode>=400) V1i^#;
{ #cikpHLXG
processErrorCode(responseCode); t&yuo E
return -2; //-2 represent access is error 5s0`T]X-
} +pv..\
i'ZnU55=
u9 *ic~Nh
String sHeader; G=Xas"|
5a5JOl$8
4X:mb}(
for(int i=1;;i++) <e|B7<.
{ o`~,+6]D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7 }t=Lx(
//Utility.log(in.readLine()); wlwgYAD
sHeader=httpConnection.getHeaderFieldKey(i); RR`\q>|
if(sHeader!=null) zYis~+
{ D.F1^9Q
if(sHeader.equals("Content-Length")) 3ug>,1:6-
{ 2_6@&2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); g|]Hm*
break; pBVzmQF
} ASS<XNP
} 80U(q/H%9
else )Zvn{
break; *P12d
} rv~OfL
} I'J-)D`
catch(IOException e){e.printStackTrace ();} nS!m1&DeD
catch(Exception e){e.printStackTrace ();} >)`*:_{
KrTlzbw&p\
.%\R L/
Utility.log(nFileLength); $-]9/Ct
u\K`TWb%
lo7>$`Q
return nFileLength; ?+]
} L$]Y$yv
w~AO;X*Ke"
{FNCC*=
//保存下载信息（文件指针位置） yTWicW7i
private void write_nPos() 4f213h
{ }.A \;FDyj
try{ {o%OG/!1
output = new DataOutputStream(new FileOutputStream(tmpFile)); R|\kk?,u
output.writeInt(nStartPos.length); 9KL)5_6 M
for(int i=0;i<nStartPos.length;i++) tac_MtW?
{ `:gXQmt
// output.writeLong(nPos); UE/iq\a>
output.writeLong(fileSplitterFetch.nStartPos); oJc v D
output.writeLong(fileSplitterFetch.nEndPos); ?,r}@89pY
} Qj9'VI>&
output.close(); SG)|4$"
} tv9 R$-cJ
catch(IOException e){e.printStackTrace ();} 6(B[(Af
catch(Exception e){e.printStackTrace ();} >Qf`xUZ
} #%/0a
'V4B{n7h
Jb!s#g
//读取保存的下载信息（文件指针位置） @i>4k
private void read_nPos() xy^z_`
{ 1?y QjW,
try{ AHplvksb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); e1H2w? s
int nCount = input.readInt(); _dVA^m
nStartPos = new long[nCount]; 69Q#UJ
nEndPos = new long[nCount]; W>$mU&ew[
for(int i=0;i<nStartPos.length;i++) uF@DJX}>
{ DbN_(mC
nStartPos = input.readLong(); VpxsgCS
nEndPos = input.readLong(); c*V/2" 5
} Q/l388'
input.close(); 0fw>/"v
} Zx|VOl,;
catch(IOException e){e.printStackTrace ();} E7U.>8C
catch(Exception e){e.printStackTrace ();} xQs._YY
} X<:Zx#J?i
7!g4`@!5M
V4?]NFK
private void processErrorCode(int nErrorCode) U5;Y o+z
{ p v*f]Yzx
System.err.println("Error Code : " + nErrorCode); p=dM2>
} ov Wm}!r
FQB6` M
WHR6/H
//停止文件下载 Hy2~D:34
public void siteStop() xtd1>|
{ AYoLpes
bStop = true; ^%RIz!}
for(int i=0;i<nStartPos.length;i++) f!}e*oX
fileSplitterFetch.splitterStop(); MJcWX|(y
?,UO$#Xm
NvJ}|w,Z
} oazy%n(KZ
} 'Fa~l'G7X
//负责部分文件的抓取 cx+%lco!
**FileSplitterFetch.java TxmKmZ u
*/ RxGZ#!j/
package NetFox; s,8g^aF4
SuJ4)f;'0
'dd[=vzK
import java.io.*; gYa (-o
import java.net.*; n{z!L-x^b
3Ebkq[/*%
4nD U-P#f
public class FileSplitterFetch extends Thread { CQET
TE@bV9a
90 pt'Jg
String sURL; //File URL ~=c[?:
long nStartPos; //File Snippet Start Position N'M+Z=!
long nEndPos; //File Snippet End Position '8"$:y
int nThreadID; //Thread's ID hWiBLip,z
boolean bDownOver = false; //Downing is over \aGTi pB
boolean bStop = false; //Stop identical fTV3lyk
FileAccessI fileAccessI = null; //File Access interface T@on ue7
DZU} p
@HP7$U"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException $McbVn)~f
{ @<=<?T>1
this.sURL = sURL; 9Z.WR-}
this.nStartPos = nStart; K7]+. f
this.nEndPos = nEnd; *l8:%t\
nThreadID = id; t|cTl/i 4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u\}"l2 r
} Xs$UpQo
Mzj|57:gx
"S0WFP\P+
public void run() aF:|MTC(~
{ K`twbTU
while(nStartPos < nEndPos && !bStop) FSkz[D_}
{ McRfEF\
~|=goHmm[
@x/D8HK2
try{ wT^QO^.
URL url = new URL(sURL); S,^)\=v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r( 8!SVX
httpConnection.setRequestProperty("User-Agent","NetFox"); 1zJ)x?
String sProperty = "bytes="+nStartPos+"-"; "']|o~B
httpConnection.setRequestProperty("RANGE",sProperty); c>yqq'
Utility.log(sProperty); //-;uEO
U<.,"`=l
$g]'$PB
InputStream input = httpConnection.getInputStream(); bv4G!21]*;
//logResponseHead(httpConnection); W3 2]#M=
>Ef{e6
vFl06N2
byte[] b = new byte[1024]; ~Jx0#+z9V
int nRead; P^& =L&U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (@;=[5+
{ gSXidh}^
nStartPos += fileAccessI.write(b,0,nRead); :B5M#D!dO
//if(nThreadID == 1) ^U]B&+m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;wj8:9 ;
} QX|y};7\e
<~-cp61z;
=.8fES
Utility.log("Thread " + nThreadID + " is over!"); v0'`K 5M
bDownOver = true; "/qm,$
//nPos = fileAccessI.write (b,0,nRead); I2<5#|CXpZ
} >sm<$'vZ/
catch(Exception e){e.printStackTrace ();} -)$5[jM]
} )~H&YINhn
} 2H2Yxe7?-
PNhxF C.
[vyi_0[
//打印回应的头信息 _/@u[dWeL
public void logResponseHead(HttpURLConnection con) KBy*QA
{ SH/^qDT'
for(int i=1;;i++) ?Y\hC0a60
{ -5sKJt]+i
String header=con.getHeaderFieldKey(i); .%T.sQ
if(header!=null) p1B~F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zJX _EO
Utility.log(header+" : "+con.getHeaderField(header)); db0]D\
else ])H[>.?K
break; XPsRa[08WK
} TjLW<D(i>
} Vs@H>97,G
J0O wzO
xty)*$C>
public void splitterStop() o-r00H|
{ Z@QJ5F1y
bStop = true; ylwh_&>2
} |++\"g
/O&{fo
xmBGZ4f%
} B4 +A
U)iq
s\3OqJo%)
/* +/4wioGm
**FileAccess.java :*dfP/GO
*//文件访问(定位，写) &_W~d0
package NetFox; n|AV7c
import java.io.*; `T(T]^C98
?$Jj^/luD
5><KTya?=
public class FileAccessI implements Serializable{ 8q_"aa,`
)H|cri~D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O6Mxp-
RandomAccessFile oSavedFile; G"D=ozr
long nPos; vj hh4$k
&$8YW]1M
W~qVZ(G*U
public FileAccessI() throws IOException |cIv&\ x
{ W2T6JFv
this("",0); VL2+"<
} ^&Wa? m.
O#72h]
A8U\/GP
public FileAccessI(String sName,long nPos) throws IOException o#9Q
{ /;clxtus
oSavedFile = new RandomAccessFile(sName,"rw"); c4Wl^E8
this.nPos = nPos; ?{rpzrc!*
oSavedFile.seek(nPos); cbaa*qoU
} \k>1q/T0V
;\(X;kQi
Td,s"p>Vq
public synchronized int write(byte[] b,int nStart,int nLen) iWp 6^g
{ S\R5SRE
int n = -1; + [~)a4#
try{ fe8}2#<o
oSavedFile.write(b,nStart,nLen); 2pmqP-pKd
n = nLen; +Hkr\
} 5VjO:>
catch(IOException e) $~)YI/b
{ W@FSQ8b>$m
e.printStackTrace (); 0AD8X+M{P
} ,jq:%Y[KZ
:b`ywSp`
5N(OW:M
return n; xZ(ryE%
} }BI|M_q.1~
ae0t*;~
(d>}Fp
} DVz_;m6)
p-XO4Pc6
L25%KGg'o
/* )18C(V-x
**SiteInfoBean.java ToX--w4
*/ Jp"yb`w
package NetFox; o1Nfn'!3/>
LDh,!5G-M
}*?,&9/_)
public class SiteInfoBean { Fxv5kho
mnL+@mm
nZ %%{#T7
private String sSiteURL; //Site's URL 5jAS1XG
private String sFilePath; //Saved File's Path %00cC~}4
private String sFileName; //Saved File's Name (z 9M
private int nSplitter; //Count of Splited Downloading File )f,9 h
m^gxEPJK
#7['M;_
public SiteInfoBean() }inV)QQ
{//nSplitter的缺省值为5 C`qE ,2.
//default value of nSplitter is 5 ,Q<mU4
this("","","",5); ~'v9/I-"
} 7j8lhrM}^
53WCF[
__Zex5Y#-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mx5#K\
{ qPBOt;N
sSiteURL= sURL; )kDB*(?
sFilePath = sPath; PUmgcMt
sFileName = sName; FxmHy{JG
this.nSplitter = nSpiltter; V{UY_ e8W
x;{Hd;<YF
K5!OvqzG
} }#h`1 uV
#Q'#/\5
`j8pgnY>5~
public String getSSiteURL() Cy dV$!&mP
{ +w/B3b
return sSiteURL; b/?)_pg
} 2N{^V?:
4W#DLip9
+{0v@6<(02
public void setSSiteURL(String value) >&ENrvaJ
{ 0f#xyS 3
sSiteURL = value; ?Wc+ J4
} X0Wx\xDg[
ohjl*dw
|A\o
public String getSFilePath() C5g9Gg
{ ! (Q[[M
return sFilePath; $0k7W?tu
} lffw "
X;n09 L`CB
b]
public void setSFilePath(String value) sI.p( -KQ
{ 0O[le*3b
sFilePath = value; YSrjg|k*
} &\%\"Zh
""A6n{4
[bw1!X3
public String getSFileName() n?;h-KKO:
{ SlG^ H
return sFileName; j WSgO(y
} }Ogb|8
bh(}f.@ 9
?)T@qn+
public void setSFileName(String value) @]!9;?so
{ 6_:I~TTX
sFileName = value; Fv*Et-8tN5
} e_"m\e#N
ut#pg+#Q
5mS/,fs@
public int getNSplitter() k*v${1&
{ a@J/[$5
return nSplitter; sY4q$Fq
} CF 3V)3}
zU0SlRFu
H32o7]lT
public void setNSplitter(int nCount) 9c%CCZ
{ \t5_V)P
nSplitter = nCount; !9.FI{W
} Ii&p v
} {,u})U2
*nYg-)
"7'P Lo3O
/* s/B_
**Utility.java w51l;2$des
*/ U>OAtiq JX
package NetFox; cK >^8T^
684|Uuf7
R$+p4@?S
public class Utility { }LeS3\+UHl
:t<S
Bgn%d4W;G
public Utility() vw4b@v-XQ3
{ _-3n'i8
>cLh$;l
no W]E}nN
} |}.}q
zvVo-{6
//线程睡眠 t0GJ$])
public static void sleep(int nSecond) f%i%QZP
{ 8*x=Fm,Ok
try{ YYT#{>&
Thread.sleep(nSecond); x NjQ"'i8
} eWNg?*/
catch(Exception e) CmV &+C$V%
{ !\$V?*p7
e.printStackTrace (); !^ad{#|X
} 7BL)FJ]UR]
} TQmrL
M9afg$;.xe
//日志 DIw_"$'At
public static void log(String sMsg) -U\'Emu4
{ r@m]#4
System.err.println(sMsg); %B( rW?p&
} Uqb]&2
Dk>6PBl
".%d{z}vz
public static void log(int sMsg) d#]hqy
{ :vX%0|
System.err.println(sMsg); Fi67"*gE
} N'WC!K.e
} J{.UUw9Agd
\1LfDlQk)
o<%0|n_O&
/* ^!d0abA
**TestMethod.java S1I.l">P
*/ k=[s%O6H
package NetFox; 92t.@!m`
-fl6M-CYX
} ck<R
public class TestMethod { ruGeN
M;,$ )>P
]gg(Z!|iQ
public TestMethod() PCHspe9!y
{ ///xx/weblogic60b2_win.exe -F[@)$L
try{ QF\nf_X
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ei):\,Nv
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |oke)w=gn
SiteFileFetch fileFetch = new SiteFileFetch(bean); QxdC[t$Lp
fileFetch.start(); B~N3k
} \0d'y#Gp*
catch(Exception e){e.printStackTrace ();} Hcwfe=K&/
aY#?QjL
[5& nH@og
} #MlpOk*G
Y}v3J(l
U31@++C[
public static void main(String[] args) <K`E*IaW
{ j7gw?,
new TestMethod(); xsn=Ji2 F
} 3,Yr%`/5'
} Uu5(/vw]
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