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)); pHoEa7:
} 4nAa`(62
for(int i=0;i<nEndPos.length-1;i++) R0oKbs{
{ :{(w3<i
nEndPos = nStartPos[i+1]; $<ld3[l i
} ~^+0
nEndPos[nEndPos.length-1] = nFileLength; W d0NT@
} ]tY ^0a
} Dde]I_f}
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N25V]
//启动子线程 ;;A2!w{}[i
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 97)/"i e
for(int i=0;i<nStartPos.length;i++) m[k_>e\u
{ 85;b9k&\M
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GJqE!I,.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9;xM%
nStartPos,nEndPos,i); TNJG#8n%Y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MQKfJru7
fileSplitterFetch.start(); .5!t:FPOv
} uytE^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Et_V,s<|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0|; .6\
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", K!,<7[MBg
nEndPos = " + nFileLength); HK+/:'Pu
// fileSplitterFetch[nPos.length-1].start(); jSc#+_y
(@WA1oNG
0EJ(.8hwm
//等待子线程结束 5JhdVnT_
//int count = 0; :NJ(r(QG>
//是否结束while循环 US
boolean breakWhile = false; hQNe;R5
.G o{1[
F7")]q3I~
while(!bStop) 5[n(7;+gw
{ gl&5l1&
write_nPos(); r < cVp^
Utility.sleep(500); 3Tq\BZ
breakWhile = true; ^9-&o
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for(int i=0;i<nStartPos.length;i++) ,C {*s$
{ fh^lO ^
if(!fileSplitterFetch.bDownOver) -7!&@wuQ
{ #Km:}=
breakWhile = false; {647|j;e
break; y$<Vha
} ttXjn
} L,;D@Xi
if(breakWhile) N N|u_
break; ];%0qb
KsrjdJx, '
2YuN~-
//count++; %& _V0R\k
//if(count>4) c]B$i*t
// siteStop(); <5=JE*s$NS
} /*Qq[C
*-s,. F+c
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System.err.println("文件下载结束！"); (Z5##dS3
} @E.k/G!~Nb
catch(Exception e){e.printStackTrace ();} ) _ I,KEe
} #.[AK_S5&
8.bKb<y
JY!l!xH(6
//获得文件长度 7=]i~7uy
public long getFileSize() , *qCf@$I
{ +\Q?w?DE|
int nFileLength = -1; =uDgzdDyE
try{ <}6{{&mT4
URL url = new URL(siteInfoBean.getSSiteURL()); Jgu94.;5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1c+]gIe
httpConnection.setRequestProperty("User-Agent","NetFox"); {YUIMd!Y
!EQ@#qW/
3sCFHn#c
int responseCode=httpConnection.getResponseCode(); 5X.e*;
if(responseCode>=400) fJZp?e"
{ 0b91y3R+
processErrorCode(responseCode); (Toq^+`c
return -2; //-2 represent access is error d*pF>j
} wB>r(xQ'
L!_ZY
;v
String sHeader; ;V<iL?
DP/J(>eG
$hxNhI
for(int i=1;;i++) }bU8G '
{ ``ekR6[8c
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *Ywpz^2?:
//Utility.log(in.readLine()); T!W~n ZC
sHeader=httpConnection.getHeaderFieldKey(i); R_sC! -
if(sHeader!=null) 2wqk,c[]
{ .lhn;*Yi
if(sHeader.equals("Content-Length")) ^[Cv26
{ ~7!7\i,Y8\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v&FF|)$
break; yk2!8
} 97!>%d[0
} z'p:gv]
else l8K5k:XCU3
break; 27ckdyQx
} >MJ?g-
} KNgH|5Pb
catch(IOException e){e.printStackTrace ();} }B7K@Wu#
catch(Exception e){e.printStackTrace ();} |_u8mV
^7]"kg DA
fQ>4MKLw=d
Utility.log(nFileLength); QH]M
hl&-\dc+
g/=K.
return nFileLength; t0:AScZY
} 6I_Hd>4
-oz`"&%
^BZkHAp
//保存下载信息（文件指针位置） bU 63X={
private void write_nPos() ,D6v4<jh
{ m\/(w_/?
try{ vhr+g 'tf
output = new DataOutputStream(new FileOutputStream(tmpFile)); }G$]LWgQx
output.writeInt(nStartPos.length); U-wLt(Y<
for(int i=0;i<nStartPos.length;i++) t)oapIeIe
{ "x'),
// output.writeLong(nPos); B@Nt`ky0*
output.writeLong(fileSplitterFetch.nStartPos); h?\2_s
output.writeLong(fileSplitterFetch.nEndPos); b=a!j=-D
} ea=83 Zj
output.close(); 'cDx{?
} cD1o"bq
catch(IOException e){e.printStackTrace ();} !e#xx]v3
catch(Exception e){e.printStackTrace ();} ihT~xt
} URcR
Uh.Zi3X6}6
}W)=@t
//读取保存的下载信息（文件指针位置） 6)]f6p&e
private void read_nPos() }wSi~^*
{ h!&sNzX
try{ PU9`<3z5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `P+(&taT
int nCount = input.readInt(); 0JRD
nStartPos = new long[nCount]; 9+YD!y
nEndPos = new long[nCount]; 5H,G-
for(int i=0;i<nStartPos.length;i++) #iSFf
{ r^$~>!kZ|
nStartPos = input.readLong(); ]Pn!nSg
nEndPos = input.readLong(); 09M;}4ev&7
} :&'{mJW*{t
input.close(); |P6EO22p
} /7$mxtB5%L
catch(IOException e){e.printStackTrace ();} '!vc/Hw
catch(Exception e){e.printStackTrace ();} $mco0%$
} MWuXI1
B'>*[!A
{gf>*
private void processErrorCode(int nErrorCode) 9CUimZ
{ z)F#u:t
System.err.println("Error Code : " + nErrorCode); D_|B2gdZY
} zW{ 6Eg
w'Z!;4E0
|U[y_Y\a
//停止文件下载 1TqF6`;+
public void siteStop() >3;^l/2c
{ o%(bQV-T
bStop = true; <z#BsnjW{
for(int i=0;i<nStartPos.length;i++) hQh9ok8S
fileSplitterFetch.splitterStop(); i8V0Ty4~N
m^!Sv?hV
eVnbRT2y&
} 1czG55 |
} 9n}A ^
//负责部分文件的抓取 5S/>l_od$2
**FileSplitterFetch.java G_oX5:J*
*/ :B#EqeI
package NetFox; jOv"<
`\FI7s3b
<GWR7rUH
import java.io.*; QJ4AL3 ^6
import java.net.*; 6zYaA
{*=E?oF@
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public class FileSplitterFetch extends Thread { GfsBQY/
~"mj;5Id
vnsSy33K
String sURL; //File URL BF|*"#s
long nStartPos; //File Snippet Start Position Z*bC#s?
long nEndPos; //File Snippet End Position )bW5yG!
int nThreadID; //Thread's ID 7Jx%JgF
boolean bDownOver = false; //Downing is over .w'vD/q;
boolean bStop = false; //Stop identical g3rRhS
FileAccessI fileAccessI = null; //File Access interface w??c1)
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:o\5K2]:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `C<F+/q
{ T'R,vxP)\
this.sURL = sURL; :ej_D}
this.nStartPos = nStart; =h\E<dw
this.nEndPos = nEnd; ~L){O*Z
nThreadID = id; + zDc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .YiaXP
} "A7<XN<
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public void run() /| f[us-w
{ ;Vo mFp L
while(nStartPos < nEndPos && !bStop) 66dTs,C
{ \1{_lynD
P CsK()
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try{ L<E/,IdE
URL url = new URL(sURL); poY8 )2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qL>v&Rd<
httpConnection.setRequestProperty("User-Agent","NetFox"); 'fl(N2t
String sProperty = "bytes="+nStartPos+"-"; RO$*G jQd
httpConnection.setRequestProperty("RANGE",sProperty); ]+lF=kkc%
Utility.log(sProperty); \4@a
'RQiLUF
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InputStream input = httpConnection.getInputStream(); +I.v!P!^
//logResponseHead(httpConnection); @SQceQfB
'8={ sMy
Fva]*5
byte[] b = new byte[1024]; S| "TP\o
int nRead; PHl4 vh#E!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uH] m]t
{ XC}1_VWs
nStartPos += fileAccessI.write(b,0,nRead); :3gFHBFDj
//if(nThreadID == 1) (k#t}B[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); * 2%oZXF
} [U']kt
UhBz<>i;!
#8&#E?^d
Utility.log("Thread " + nThreadID + " is over!"); Hi7G/2t@`
bDownOver = true; d1lH[r!Z
//nPos = fileAccessI.write (b,0,nRead); "Y(%oJS]D
} ]]3Q*bq4
catch(Exception e){e.printStackTrace ();} q!@c_o
} DzE E:&*=
} U-ULQ|6U
|QMT A5
Y}ky/?q
//打印回应的头信息 @QX4 \
public void logResponseHead(HttpURLConnection con) ME,duY/>Q
{ 8ur_/h7
for(int i=1;;i++) r.Lx%LZ\^
{ sHF%=Vu
String header=con.getHeaderFieldKey(i); '1lx{UzD
if(header!=null) G-sa L*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cY^Y!.,
Utility.log(header+" : "+con.getHeaderField(header)); g.=!3e&z%
else 6iyt2qkh
break; Jb6&
} qWkx:-g]
} W -3w7^
o=@ UXi
Hj1k-Bs&'w
public void splitterStop() W >Kp\tD
{ ;wpW2%&
bStop = true; 0x6@{0
} }:"R-s
ELD +:b
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} 83X/"2-K
75PS^5T,
oX2r?.j#M
/* )y5iH){!
**FileAccess.java FmR\`yY_,
*//文件访问(定位，写) lej^gxj/2
package NetFox; ]KzJ u`O%G
import java.io.*; B piEAwh
}&=uZ:
40rZ~!}
public class FileAccessI implements Serializable{ "_Zh5 g
mJ/^BT]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 QK,=5~IJ
RandomAccessFile oSavedFile; C?bXrG\
long nPos; i^~sn `o
v)TUg0U=,
$.=5e3
public FileAccessI() throws IOException &C\=!r0j^
{ ;%M2x5
this("",0); [+yGDMLs
} ,CN#co
?#x'_2
7Z9.z4\
public FileAccessI(String sName,long nPos) throws IOException "hJ7 Vv_
{ {P,>Q4N
oSavedFile = new RandomAccessFile(sName,"rw"); aS2a_!f
this.nPos = nPos; 8U8P g2
oSavedFile.seek(nPos); JB641nv
} L)@`58Eil
g6HphRJ5s
T,A!5V>cX
public synchronized int write(byte[] b,int nStart,int nLen) ~>lOl/n5
{ nqBG]y aI
int n = -1; :LU"5g
try{ !>?4[|?n<
oSavedFile.write(b,nStart,nLen); JvT%R`i
n = nLen; N;e}dwh&
} /vMQF+
catch(IOException e) I=Gr^\x=
{ "tEj`eR
e.printStackTrace (); \z&03@Sw
} J{aQ1)
tvGg@Xs\
hqdC9?\
return n; `8.1&fBr
} 0-6:AHix
SjFF=ib
qQwJJjf
} y^5T/M
Zb12:?
Cmp{FN"o
/* R?1idl)
**SiteInfoBean.java "6 uTo0
*/ ee4KMS
package NetFox; nNkyOaK*4
:Bdipc
@&/s~3
public class SiteInfoBean { 3U :YA&K(
cg>!<T*
k8!hvJ)?
private String sSiteURL; //Site's URL UUt~W
private String sFilePath; //Saved File's Path @2-Hj~
private String sFileName; //Saved File's Name s|fCR
private int nSplitter; //Count of Splited Downloading File jAD+:@
m9\@kA
z36brv<_'p
public SiteInfoBean() -6.i\ B
{//nSplitter的缺省值为5 {o Q(<&Aw
//default value of nSplitter is 5 Yg\{S<wr
this("","","",5); 5]A$P\7~1
} P]~N-xdV
m^W*[^p
~N)( ^ 4
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (MF+/fi
{ ^TuP=q5?
sSiteURL= sURL; 44<9zHK
sFilePath = sPath; bW,BhUb,|
sFileName = sName; E#IiyZ
this.nSplitter = nSpiltter; N>W;0u!
7C,<iY
r{;VTQ
} ~*,Ddwr0a
uD0(aqAZ
)&b}^1
public String getSSiteURL() LS R_x$G+t
{ ej)BR'*
return sSiteURL; FF~on06!
} OX#eLco
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public void setSSiteURL(String value) 0xvMR&.H
{ ox i a}
sSiteURL = value; gNMKGf\Y
} ^?sSsHz
VuJfo9 `E
e>ZbZy?
public String getSFilePath() 0{^l2?mgSb
{ L@d]RMNv
return sFilePath; :V5!C$QV
} wI1M0@}PV
Fyi?,,
y{&{=1#
public void setSFilePath(String value) |,M#8NOp:
{ T6/$pJl
sFilePath = value; S\yu%=h
} \S|VkPv
i4{ /
H`+]dXLB
public String getSFileName() r-1yJ
{ B^_$ hJncc
return sFileName; mlsvP%[f.
} gavQb3EP
p3,(*eZ
ZYl-p]\*y
public void setSFileName(String value) 6I5[^fv45G
{ )Ta]6
sFileName = value; YKs^%GO+
} \pBYWf
@@&@}IQcR1
j:de}!wc
public int getNSplitter() &\WkJ}&PnA
{ n{qa]3
return nSplitter; "R\\\I7u
} ^Yf)lV&[
dctA`W@:-
(|ct`KU0#
public void setNSplitter(int nCount) lyOrM7Gs
{ y<'2BTf
nSplitter = nCount; bSeL"
} $Nt]${0
} #C=L^cSx(
2S7H_qo$
m\}\RnZu
/* =oKPMmpCZ
**Utility.java <Vr]2mw
*/ )P(d66yq'u
package NetFox; ]VHdE_7)
e5"-4udCn
iBPdCp%]`
public class Utility { tswG"1R
iC5JU&l
x9{Sl[2&
public Utility() /FNj|7s
{ C7fi1~
!kHyLEV
,pGCgOG#}c
} u1pYlu9IW
VW<"c 5|
//线程睡眠 NZw[.s>n
public static void sleep(int nSecond) J~yd]L>
{ *fuGVA
try{ zM9).D H
Thread.sleep(nSecond); 644hQW&W
} AIRVvW~($
catch(Exception e) zvQ^f@lq2
{ Sj]T{3mi
e.printStackTrace (); MIua\:xT
} m?kIa!GM=
} 7Hr4yh[j&
At^DY!3vx
//日志 NGb!7Mu9
public static void log(String sMsg) S#%JSQo:
{ pFv[z':&Q
System.err.println(sMsg); >/OXC+=^4
} Ph7(JV{
U%B]N@
C}DG'z9
public static void log(int sMsg) v,x%^gv0
{ ~M9n<kmE
System.err.println(sMsg); \SHD
} KSpC%_LC
} :0TSOT9.
xx`8>2T#e
J!^~KN6[
/* OD@@O9
**TestMethod.java {/|8g(
*/ nD?M;XN
package NetFox; $0`$)(Y
k~s>8N:&G
<K.C?M(9
public class TestMethod { $xn%i\
(=&bo p
J/P@m_Yx
public TestMethod() +EB,7<5<
{ ///xx/weblogic60b2_win.exe 1-Wnc'(OK
try{ ?PxYS%D_L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J'Mgj$T $
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IkXKt8`YVA
SiteFileFetch fileFetch = new SiteFileFetch(bean); |EEz>ci
fileFetch.start(); S bqM=I+
} '>WuukC
catch(Exception e){e.printStackTrace ();} YvP"W/5
o!_; H}pq
Qj~W-^/ -
} (9[C0eS
[{!j9E?(
$E@.G1T [
public static void main(String[] args) -9<yB
{ 4;~lpty
new TestMethod(); 2.L6]^N p(
} dgqJ=+z 0y
} ^9V8M9
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