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)); GdG%=+
} |i|YlWQS
for(int i=0;i<nEndPos.length-1;i++) EF"ar
{ T?AGQcG
nEndPos = nStartPos[i+1]; Y1`.
} s$H5W`3
nEndPos[nEndPos.length-1] = nFileLength; ;lYO)Z`3\
} Mh~T.;f.qq
} V9Au\
MYN1zYT6j
8^dGI9N
//启动子线程 YQQ!1hw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; YgM6z K~
for(int i=0;i<nStartPos.length;i++) {H])Fob
{ PDD` eK}Fj
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g:[&]o} :9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6Otv[8^}
nStartPos,nEndPos,i); }ZVNDvGH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /jj@ =H
fileSplitterFetch.start(); U-WrZ|-
} \R79^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p-*BB_J"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Xo%Anqk
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fi bR:8
nEndPos = " + nFileLength); 3g-}k
// fileSplitterFetch[nPos.length-1].start(); tCc}}2bC&
h$ZF[Xbfe
1"v;w!uh
//等待子线程结束 1d\K{ 7i#
//int count = 0; *,'"\n
//是否结束while循环 t8?+yG;
boolean breakWhile = false; N"E\o,_
ioa 1n=j
i w m7M
while(!bStop) P]6pPS
{ c$e~O-OVD?
write_nPos(); fcw\`.
Utility.sleep(500); .zegG=q
breakWhile = true; Llk`
9 z3Iwl
{<kl)}
for(int i=0;i<nStartPos.length;i++) :"QRB#EC%
{ w~Y#[GW
if(!fileSplitterFetch.bDownOver) 2ZE4^j|
{ 6PPvfD^
breakWhile = false; (>;~((2
break; }:jXl!:V
} UI!EIZ*~
} uk\GAm@O
if(breakWhile) pn =S%Qf]
break; gl!3pTC
l;|1C[V
8=2)I.
//count++; P AKh v.7
//if(count>4) mS%D" e
// siteStop(); SnXYq7`t
} ~V./*CQ\c
D2?7=5DgS
lT(MywNsg
System.err.println("文件下载结束！"); Y:byb68
} ?iia
catch(Exception e){e.printStackTrace ();} Zmp ^!|=X!
} h[lh01z
N86Hn]#
lq%s/l
//获得文件长度 #[i({1`^L
public long getFileSize() 9JUlu
{ /\=g;o'
int nFileLength = -1; _Y~+ #Vc
try{ .79'c%3}
URL url = new URL(siteInfoBean.getSSiteURL()); }2h~o~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YE^|G,]
httpConnection.setRequestProperty("User-Agent","NetFox"); Ybok[5
6~2!ZU
$Z;0/\r%
int responseCode=httpConnection.getResponseCode(); EL+}ab2S
if(responseCode>=400) ;ga~ae=Fg
{ Z+vLEEX*uQ
processErrorCode(responseCode); 4)"jg[
return -2; //-2 represent access is error N*$Q(K
} e{?~m6
5q8bM.k\7N
].Et&v
String sHeader; \?GMtM,
3-Ti'xM
.IYE"0)wJ
for(int i=1;;i++) yt<K!=7&
{ ^ 5UIbA(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qb SX'mx<
//Utility.log(in.readLine()); c5t?S@b
sHeader=httpConnection.getHeaderFieldKey(i); "0]i4d1l
if(sHeader!=null) V= .'Db2D
{ W{0<ro`
if(sHeader.equals("Content-Length")) D vK}UAj=
{ p oNQ<ijK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l$zM|Z1wR`
break; PVU(RJ
} {j^}"8GB
} D&]SPhX
else ci*Z9&eS+
break; X"[c[YT!%[
} >Ks|yNJ
} #|gt(p]C
catch(IOException e){e.printStackTrace ();} P [gqv3V
catch(Exception e){e.printStackTrace ();} D+k5e=
scA&:y
pET5BMxGG
Utility.log(nFileLength); 8-po|
PR.?"$!D{
^(a%B
return nFileLength; 0P!6 .-XU
} QRa>W/N
!qy/'v4
)WBTqML[
//保存下载信息（文件指针位置） C9*'.~
private void write_nPos() _STN^
{ A!hkofQ
try{ DMf:u`<
output = new DataOutputStream(new FileOutputStream(tmpFile)); :GO}G`jY
output.writeInt(nStartPos.length); \]o#tYN\a0
for(int i=0;i<nStartPos.length;i++) yyBy|7QgO
{ Qs*g)Yr
// output.writeLong(nPos); Y.=v!*p?}
output.writeLong(fileSplitterFetch.nStartPos); M3x%D)*
output.writeLong(fileSplitterFetch.nEndPos); o,u-%
} Q;`#ujxL
output.close(); p5Y"W(5_
} r6j 3A
catch(IOException e){e.printStackTrace ();} `F(KM '
catch(Exception e){e.printStackTrace ();} ^ b}_[B
} bl:.D~@
jYuH zf
&grT}
//读取保存的下载信息（文件指针位置） -4"E]f
private void read_nPos() Oi=kL{DG:s
{ up`!r;5-
try{ {6A3?q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); LUJKR6oT{>
int nCount = input.readInt(); :3u>%
nStartPos = new long[nCount]; @@_f''f$
nEndPos = new long[nCount]; @Vc*JEW
for(int i=0;i<nStartPos.length;i++) `|Tr"xavf
{ k%JwS_F
nStartPos = input.readLong(); JZN'U<R
nEndPos = input.readLong(); 41,Mt
} W}nD#9tL
input.close(); $I+QyKO9k
} HPm12&8,
catch(IOException e){e.printStackTrace ();} C:zK{+
catch(Exception e){e.printStackTrace ();} @ Al\:
} nIKh<ws4z
^P$IDJCo
?r#e
private void processErrorCode(int nErrorCode) EubF`w$KWX
{ .J'}qkz~
System.err.println("Error Code : " + nErrorCode); T/uj5pMG
} Wu9@Ecb
Al6)$8]e
oJ>]=^?k
//停止文件下载 %Qrf ]
public void siteStop() <<Ut@243\
{ (*BQd1Z
bStop = true; EO3?Dev
for(int i=0;i<nStartPos.length;i++) 7k{C'\m
fileSplitterFetch.splitterStop(); iIA&\'|;i
'$;S?6$eW
jBarYg
} Hj$JXo[U
} 6:#zlKYJ
//负责部分文件的抓取 i4&"-ujrm
**FileSplitterFetch.java Tf<1Z{9
*/ F3i+t+Jt
package NetFox; 4tof[n3us
z45ImItH
$9j\sZj&
import java.io.*; ; Sq_DP1W
import java.net.*; tJ i#bg%
b_:]Y<{> f
9v8{JaI3
public class FileSplitterFetch extends Thread { TE3A(N'
iE!$7y
-:dUD1
String sURL; //File URL g,r'].Jg
long nStartPos; //File Snippet Start Position #jv~FR`4v^
long nEndPos; //File Snippet End Position 8dNwi&4
int nThreadID; //Thread's ID $&I##od
boolean bDownOver = false; //Downing is over S{zi8Oc6
boolean bStop = false; //Stop identical :4;ZO~eq!
FileAccessI fileAccessI = null; //File Access interface YJ3aJ^m#E
Ao69Qn
{+F/lN@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bM;==W
{ ]ECzb/
this.sURL = sURL; @~qlSU&
this.nStartPos = nStart; u`O xY
this.nEndPos = nEnd; P=OHiG\z
nThreadID = id; #;# V1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4 >at#Zc
} yF0\$%H>$
9,sj,A1
"k o?AUt
public void run() Lo5itW
{ K?8{y
while(nStartPos < nEndPos && !bStop) rzsb(
{ 8vOKm)[%
c,:xm=&
6-c3v
try{ :GBWQXb G
URL url = new URL(sURL); & gnE"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,`ST Va-
httpConnection.setRequestProperty("User-Agent","NetFox"); F#*vJb)
String sProperty = "bytes="+nStartPos+"-"; *$1M=$
httpConnection.setRequestProperty("RANGE",sProperty); u^8:/~8K
Utility.log(sProperty); @`^+XPK\
0&} "!)
wt0^R<28
InputStream input = httpConnection.getInputStream(); B"ZW.jMaI
//logResponseHead(httpConnection); .DiH)
8*-8"It<"
tpwMy:<Ex
byte[] b = new byte[1024]; 7O^ySy"l
int nRead; mEyJ o|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]3uErnI
{ Ne!F p
nStartPos += fileAccessI.write(b,0,nRead); mtSOygd
//if(nThreadID == 1) ,u8)g;8s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ms@*JCL!t
} ^V#9{)B
FAkjFgUJp
"7mYs)=
Utility.log("Thread " + nThreadID + " is over!"); RB`Emp&T
bDownOver = true; # -e
//nPos = fileAccessI.write (b,0,nRead); WvQK$}Ax4N
} rJ|Q%utYz
catch(Exception e){e.printStackTrace ();} DN3#W w2[r
} (Z;;v|F.i=
} <5X?6*Qvr
r~&"D#)sy
SAMP,un7
//打印回应的头信息 ;jS2bc:8a
public void logResponseHead(HttpURLConnection con) FR&4i" +
{ YNyaz\L
for(int i=1;;i++) MB06=N
{ ?f<JwF<
String header=con.getHeaderFieldKey(i); %xF j;U?
if(header!=null) azF|L"-RP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (L}
Utility.log(header+" : "+con.getHeaderField(header)); rH Et]Xa
else FKRO0%M4}Z
break; #}*w &y
} 78zjC6}`
} (hWr!(>C4]
\n$s5i-
G- wQ weJ9
public void splitterStop() +aR.t@D+"Y
{ pESlBQ7{I
bStop = true; =oQw?,eY
} +y'V
^PA >t$
x(pq!+~K
} |U)m'W-(q
G347&F)
d*Q:[RUf,
/* itClCEOA
**FileAccess.java ~'>RK
*//文件访问(定位，写) E^B*:w3
package NetFox; H<T9$7Yr%r
import java.io.*; {C3AxK0
3 r4QB
|`d,r.+P7
public class FileAccessI implements Serializable{ y"q7Gx*^j
\9k$pC+l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l`=).k
RandomAccessFile oSavedFile; 65X31vU
long nPos; x}o]R
l}odW
t9T3e
public FileAccessI() throws IOException <{!^
{ wgfy; #
this("",0); 2r;^OWwr?
} 1&N|k;#QS
:&:IZkO
;]YQWK
public FileAccessI(String sName,long nPos) throws IOException y Nb&;E7 H
{ /xf4*zr
oSavedFile = new RandomAccessFile(sName,"rw"); :a$ZYyD
this.nPos = nPos; /!J1}S
oSavedFile.seek(nPos); vl59|W6
} BMPLL2I
cfI5KLG~#
U U!M/QJ
public synchronized int write(byte[] b,int nStart,int nLen) vQf'lEFk
{ FD>j\
int n = -1; Zkl:^!*
try{ kw)@[1U
oSavedFile.write(b,nStart,nLen); `s74g0h
n = nLen; kB_uU !G
} ]=ar&1}J
catch(IOException e) .C=&`;Vs
{ 3&i8C,u]/O
e.printStackTrace (); kcT?<r
} *4}lV8
S~^0 _?
&X0/7)*"v
return n; nsR^TD;
} uV1H iv-
bDd$79@m
bSHlR#!6
} N_S>%Z+
:()(P9?
{MX_t/o=f
/* 86d*
**SiteInfoBean.java |rJ_
*/ %4QCUc*lr
package NetFox; dLOUL9hf
N{Og; roGD
xR+=F1y
public class SiteInfoBean { f:iK5g
Ht^MY
=w&%29BYq
private String sSiteURL; //Site's URL [{3WHS.
private String sFilePath; //Saved File's Path ,Yhy7w
private String sFileName; //Saved File's Name $$C5Q;7w!
private int nSplitter; //Count of Splited Downloading File v|+}>g
VuTH"br6
K@xp!
public SiteInfoBean() m(JFlO
{//nSplitter的缺省值为5 (2vR8
//default value of nSplitter is 5 /_~b~3{u
this("","","",5); 'Rk~bAX
} |u8hxa
X;_0"g
c)Ft#vzg&e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Mi'Q5m
{ uYjJDLYoHl
sSiteURL= sURL; kfb+OE:7
sFilePath = sPath; 0^44${bA
sFileName = sName; 3}O.B r|
this.nSplitter = nSpiltter; g3{)AX[Uy
e #l/jFJU
Wo5G23:xz
} bu"Jb4_a>
N]cGJU>$
=DTn9}u
public String getSSiteURL() gOw|s1`2,
{ ~D@pk>I
return sSiteURL; )CS7>Vx
} AEkgm^t.{
&*g5kh{
U@[P.y~J
public void setSSiteURL(String value) Y1AbG1n|
{ EK.L>3
sSiteURL = value; }]sI?&xB
} ><iEVrpN
#I9|>XE1
DoWY*2E
public String getSFilePath() dtjaQsJM^
{ xD#PM |I
return sFilePath; lD2>`s5
} @Zd+XWFw
}4xxge?r
KmV#% d
public void setSFilePath(String value) ]OY6.m
{ yAEOn/.~
sFilePath = value; g=; rM8W
} j-$aa;
l1`Zp9I
6, ag\
public String getSFileName() <Xw 6m$fr:
{ ;}K1c+m!5V
return sFileName; ^8)&~q*
} U0u@[9!
D+rDgrv
GSV,
public void setSFileName(String value) #Q6wv/"Ub
{ S6}_Z
sFileName = value; d T/*O8
} &nn!{S^
/6F 1=O(c>
@FkNT~OZ
public int getNSplitter() &dvJg
{ 7=om /
return nSplitter; *Q=-7am
} 6N.mSnp
0]8+rWp|Nz
FVG|5'V^
public void setNSplitter(int nCount) 3leg,qd
{ H*|Bukgt/M
nSplitter = nCount; &.kg8|s{
} t,N-|
} .5L/<
s5|LD'o!
w;H
/* wO} 3i6
**Utility.java P?n!fA>!
*/ O~d!*A
package NetFox; ^'QcP5Fv
oD{V_/pdx
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public class Utility { f]T1:N*t
g/+M&k$
$$ _uQf
public Utility() hl}#bZ8]
{ KtEMH
/G[y 24 Q
\Qk:\aLR
} y(.WK8
!nVX .m9
//线程睡眠 IvIBf2D;Q
public static void sleep(int nSecond) NL&g/4A[a
{ &%u,b~cL?
try{ |BH, H
Thread.sleep(nSecond); k`)LO`))
} M#S8x@U
catch(Exception e) 3Un/-4uL
{ F]yclXf('
e.printStackTrace (); r\],5x'xSu
} ~R)w 9uq
} @{I55EQ]
"G6d'xkP
//日志 idO3/>R [
public static void log(String sMsg) G&C)`};
{ ?2EzNNcS
System.err.println(sMsg); GU&XK7L
} U\VwJ2 {i
ie.cTTOI
vp mSzh
public static void log(int sMsg) 7C2/^x P
{ Qg6m
System.err.println(sMsg); A9l^S|r
} }f&7<E
} )CR8-z1`
t1C{
1b|<
/* #s yP=
**TestMethod.java HqYaQ~Dth
*/ y_$^Po
package NetFox; G#@<bg3
;k/0N~
P\zi:]h[Gh
public class TestMethod { n+uq|sYVa
)1x333.[c
(OG@]|-
public TestMethod() mz\m^g3
{ ///xx/weblogic60b2_win.exe >MQW{^
try{ -IX;r1UD
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 82/iVm1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); K=(&iq!VO
SiteFileFetch fileFetch = new SiteFileFetch(bean); gu:..'V
fileFetch.start(); ;'o>6I7Ph
} ?N|PgNu X
catch(Exception e){e.printStackTrace ();} @XIwp2A{+
'.kbXw0}
*;gi52tM
} {Z?!*Ow
z0Zl'
Y(A?ib~K
public static void main(String[] args) |g;XC^!%=o
{ sJM}p5V
new TestMethod(); IBF>4qm"
} i-ogeR?
} pwZ &2&|
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