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)); =o(5_S.u;
} 9&2O9Nz6
for(int i=0;i<nEndPos.length-1;i++) 8^2oWC#U(
{ lv<*7BCp
nEndPos = nStartPos[i+1]; 0S_~\t
} dL 1tl
nEndPos[nEndPos.length-1] = nFileLength; 4[r0G+
} ~H_/zK6e
} nNV'O(x}
=:Fc;n>c<K
Fnv;^}\z
//启动子线程 %N6A+5H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~ 'cmSiz-
for(int i=0;i<nStartPos.length;i++) ~$cV:O7
{ Lx1FpHo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KP^V>9q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `2WFk8) F
nStartPos,nEndPos,i); )[6U^j4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xC:L)7#aw
fileSplitterFetch.start(); qJs<#MQ2
} #U4F0BdA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 286;=rN]*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L#?Ek-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4jMFr,
nEndPos = " + nFileLength); 6:5I26
// fileSplitterFetch[nPos.length-1].start(); UgNu`$m+
{X+3;&@
mHTXni<!
//等待子线程结束 ~"H,/m%2o
//int count = 0; {SPq$B_VR
//是否结束while循环 Oc#syfO
boolean breakWhile = false; tjGn|+|k
ItVWO:x&v
%6,SKg p
while(!bStop) &X ):4
{ -H@:*
write_nPos(); d#Y^>"|$.
Utility.sleep(500); P>C~ i:4n
breakWhile = true; 29"'K.r
W~;`WR;.
Lc,Pom
for(int i=0;i<nStartPos.length;i++) ~9]hV7y5C
{ ;O6;.5q&
if(!fileSplitterFetch.bDownOver) |Nn)m
{ RDi]2
breakWhile = false; Dlae;5D
break; AaOuL,l
} F?*-4I-
} ,/%=sux
if(breakWhile) e0zq1XcZ
break; wLH>:yKUU
bKY7/w<dP
gIa+5\qYY
//count++; }Yzco52
//if(count>4) )JLdO*H
// siteStop(); x%m%_2%Z
} Egp/f|y
Y|f[bw
mt{nm[D!Xp
System.err.println("文件下载结束！"); Qf+\;@
} y/cvQY0pU
catch(Exception e){e.printStackTrace ();} c /HHy,
} ?k&Vy
SI-qC
)e+>w=t
//获得文件长度 ^z IW+:
public long getFileSize() R6.hA_ih
{ C.yQ=\U2
int nFileLength = -1; HGs $*
try{ @/.;Xw]
URL url = new URL(siteInfoBean.getSSiteURL()); 6+|do+0Icg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f!uwzHA`?
httpConnection.setRequestProperty("User-Agent","NetFox"); TH&U j1
_Xc8Yg }`
Y-_`23x`
int responseCode=httpConnection.getResponseCode(); R6Km\N
if(responseCode>=400) m@2QnA[4
{ Ts[_u@
processErrorCode(responseCode); kR-SE5`Jk
return -2; //-2 represent access is error Nho>f
} L^2%1GfE{
#ym'AN
>V?eog%~
String sHeader; -`kW&I0
iDp)FQ$
+T1pJ 89P
for(int i=1;;i++) H9`)BbR
{ HZC"nb}r4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XK3tgaH
//Utility.log(in.readLine()); XkE`U5.
sHeader=httpConnection.getHeaderFieldKey(i); JV^=v@Z3
if(sHeader!=null) rNWw?_H-H(
{ 5h=}j
if(sHeader.equals("Content-Length")) %~H-)_d20
{ DFB@O|JL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WUe{vV#S'0
break; kWMl
} p Z|V 3
} x_N'TjS^{
else (l~AV9!m:
break; &tLgG4pd
} #uG%j
} Eex~xiiV
catch(IOException e){e.printStackTrace ();} x:NY\._
catch(Exception e){e.printStackTrace ();} 0WW2i{7`U
UT~4x|b:O
[I,Z2G,Jb
Utility.log(nFileLength); QC OM_$y
{tuYs:
A Ru2W1g
return nFileLength; 2/\r)$ 2i
} ArI2wM/v
~F|+o}a`
A@!qv#'
//保存下载信息（文件指针位置） r[`9uVT/
private void write_nPos() w7.V6S$Ga
{ +K:Dx!9
try{ bQg:zww
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ha0M)0Anv
output.writeInt(nStartPos.length); #C74z$
for(int i=0;i<nStartPos.length;i++) /!yU!`bY
{ OhQgF
// output.writeLong(nPos); %op**@4/t\
output.writeLong(fileSplitterFetch.nStartPos); Q^9_'t}X
output.writeLong(fileSplitterFetch.nEndPos); )Pa'UGY
} n`B:;2X,
output.close(); Ct<udO
} H7&8\FNa
catch(IOException e){e.printStackTrace ();} *MhRW,=
catch(Exception e){e.printStackTrace ();} z;,u}u}aI
} c \J:![x
ul6]!Iy
qdJ=lhHM}
//读取保存的下载信息（文件指针位置） 36&e.3/#
private void read_nPos() F4-$~v@
{ +aCv&sg
try{ w>s,"2&5J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .GPT!lDc
int nCount = input.readInt(); YNyk1cE
nStartPos = new long[nCount]; j|DsG,
nEndPos = new long[nCount]; T"}5}6rSG
for(int i=0;i<nStartPos.length;i++) XSwl Tg
{ ?|\ER#z
nStartPos = input.readLong(); [\98$BN
nEndPos = input.readLong(); ed{ -/l~j
} (&Kk7<#`
input.close(); .]Y$o^mf
} ;C9_?u~#
catch(IOException e){e.printStackTrace ();} 4<w.8rR:A
catch(Exception e){e.printStackTrace ();} JQ_sUYh~3
} +;(c:@>@,
,GhS[VJjR
,hm\
private void processErrorCode(int nErrorCode) X6w6%fzOH>
{ I3{PZhU.
System.err.println("Error Code : " + nErrorCode); CAig]=2'
} Wq D4YGN
\j}ZB<.>
R6<X%*&%
//停止文件下载 \_VA50
public void siteStop() j;+b0(53
{ $lfn(b,
bStop = true; aB2FC$z
for(int i=0;i<nStartPos.length;i++) b4%??"&<Y
fileSplitterFetch.splitterStop(); 2. NN8PPD"
DZ3wCLQtK
V# }!-Xj
} }1L4"}L.
} ,B*EVN
//负责部分文件的抓取 [: n'k
**FileSplitterFetch.java +5g_KS
*/ <Uk}o8E
package NetFox; P-9)38`5
kr^P6}'
z>1Pz(
import java.io.*; T$)^gHS
import java.net.*; r..iko]T
L:$ ,v^2
U*rcd-@
public class FileSplitterFetch extends Thread { Y#ap*
:DK {Vg6
bI7Vwyz
String sURL; //File URL P[G)sA_"
long nStartPos; //File Snippet Start Position kf\PioD8
long nEndPos; //File Snippet End Position l?v86k
int nThreadID; //Thread's ID jodIv=C
boolean bDownOver = false; //Downing is over '6nAF
boolean bStop = false; //Stop identical T8?Ghbn
FileAccessI fileAccessI = null; //File Access interface 0mYXv4 <
Di,^%
P8OaoPj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :_`F{rDB
{ \S `:y?[Y
this.sURL = sURL; y;m|
this.nStartPos = nStart; "=HA Y
this.nEndPos = nEnd; B{n,t}z
nThreadID = id; w8")w*9Lmg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9d0@wq.
} =g7x' kN
nSDMOyj+
zH72'"w
public void run() *?@?f&E/
{ ]\-A;}\e
while(nStartPos < nEndPos && !bStop) ch*8B(:
{ &@X<zWg
;>%r9pz ~
rK8lBy:<
try{ nmee 'oEw
URL url = new URL(sURL); ].avItg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <)C#_w)-
httpConnection.setRequestProperty("User-Agent","NetFox"); np|Sy;:
String sProperty = "bytes="+nStartPos+"-"; @Myo'{3vF
httpConnection.setRequestProperty("RANGE",sProperty); YH}'s>xZz
Utility.log(sProperty); nUaJzPl
'&P%C" 5
)rIwqUgp6\
InputStream input = httpConnection.getInputStream(); j.[.1G*("
//logResponseHead(httpConnection); zF`0J
&Q/W~)~
L8@f-Kk
byte[] b = new byte[1024]; c`)\Pb/O
int nRead; KWbI'}_z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;HfmzY(
{ ~p6 V,Q
nStartPos += fileAccessI.write(b,0,nRead); u4cnE"
//if(nThreadID == 1) &C5_g$Ma.Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B6+khuG(
} +zqn<<9
7uqzm
Uk[b|<U-`d
Utility.log("Thread " + nThreadID + " is over!"); 3oj' ytxN
bDownOver = true; J/`<!$<c
//nPos = fileAccessI.write (b,0,nRead); ^do9*YejX;
} f#>,1,S
catch(Exception e){e.printStackTrace ();} tH@Erh|%
} #Qw0&kM7I
} .fqN|[>
5;Czu(iH$
nQZx=JK
//打印回应的头信息 +%z>H"J.
public void logResponseHead(HttpURLConnection con) Hzm:xg
{ @,j*wnR
for(int i=1;;i++) @f>-^
{ '`[&}R
String header=con.getHeaderFieldKey(i); oi7@s0@
if(header!=null) E:_ZA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nt;m+by
Utility.log(header+" : "+con.getHeaderField(header)); 3)wN))VBX
else b<[Or^X ]
break; *uRBzO}
} k!j5tsiR
} ^]Y>[[
l+K'beP
=osk+uzzG
public void splitterStop() W\$`w
{ H064BM
bStop = true; /|m2WxK)
} VOsRAn/N
IxN9&xa
XAKs0*J>
} f1RWP@iar
;vR4XHl|
un"Gozmt5
/* #6aW9GO
**FileAccess.java 4}baSV
*//文件访问(定位，写) (62"8iD6
package NetFox; w>&aEv/f
import java.io.*; !<8W {LT
' ,wFTV&
G^|:N[>B
public class FileAccessI implements Serializable{ .[KrlfI
m]0;"jeL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A/$QaB,x
RandomAccessFile oSavedFile; J$DE"|-
long nPos; ;W )Y OT
ij`w} V
MTh<|$
public FileAccessI() throws IOException A0s ZOCky
{ 2eS~/Pq5=i
this("",0); =!A_^;NQf
} %g$o/A$
^$jb7HMObI
Lnl(2xD
public FileAccessI(String sName,long nPos) throws IOException KhR81\
{ T@B/xAq5!
oSavedFile = new RandomAccessFile(sName,"rw"); /N10
this.nPos = nPos; x_Y!5yg E
oSavedFile.seek(nPos); H [\o RId
} oG?Xk%7&\
_Kf%\xg
3AtGy'NTp
public synchronized int write(byte[] b,int nStart,int nLen) q-2Bt,Y
{ ]IQ&>z}<
int n = -1; hpX9[3
try{ Hyl%mJ
oSavedFile.write(b,nStart,nLen); z (wc0I
n = nLen; Xza(k
} (*'f+R`$
catch(IOException e) &-6Gc;f8
{ *I.f1lz%*
e.printStackTrace (); ORw,)l
} S!CC }3zw
WIxy}3_to
qS$Ox?Bw#u
return n; :J@gmY:C
} V!A~K
`5.'_3
prF%.(G2)
} =z69e%.
`p-cSxR_
%)W2H^
/* G`61~F%
**SiteInfoBean.java :Yh+>c}N
*/ UKvWJnz
package NetFox; xGg )Y#
- %h.t+=U
Qbn"=n2
public class SiteInfoBean { J/aC}}5D
CYP q#rd
.@U@xRu7|
private String sSiteURL; //Site's URL i$G@R%
private String sFilePath; //Saved File's Path \V8PhO;j
private String sFileName; //Saved File's Name @o _}g !9=
private int nSplitter; //Count of Splited Downloading File *vxk@`K~
mxC;?s;~
b5vC'B-!
public SiteInfoBean() v>)"HL"XG
{//nSplitter的缺省值为5 *)T^ChD,
//default value of nSplitter is 5 #OD/$f_
this("","","",5); ,m:.-iy?
} (Zrj_P`0[
0&|\N ? 8_
E,U+o $
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kJsN|=
{ & G4\2l9
sSiteURL= sURL; mSF(q78?
sFilePath = sPath; E A1?)|}n
sFileName = sName; d#4**BM
this.nSplitter = nSpiltter; 0@iY:aF
IY\5@PVZ
b9HtR-iR;
} 6j]0R*B7`Q
m8hk:4Ae
g7`LEF <A
public String getSSiteURL() w``ST
{ <)c)%'v
return sSiteURL; 9IfmW^0
} ;))+>%SGCt
c9u`!'g`i
| rtD.,m
public void setSSiteURL(String value) oIzj,v8$
{ yI
sSiteURL = value; ,f'CD{E
} 9F;>W ET
6}Ci>_i4#
37.S\gO]
public String getSFilePath() K;H&n1
{ YfKdR"i+.
return sFilePath; 8^+%I/S$
} qWPkT$ u
rcG"o\g@+
,m|h<faZL
public void setSFilePath(String value) u^I|T.w<r6
{ j-}O0~Jz
sFilePath = value; <^jQo<kU
} '4Bm;&6M
EUX\^c]n
O;jrCB
public String getSFileName() aSQ#k;T[
{ $Sip$\+*
return sFileName; LCKV>3+_#
} i3mcx)d@H
SRDp*
p%=u#QNi
public void setSFileName(String value) )}Kf=
{ #r\4sVg
sFileName = value; .|fHy
} 4!yzsPJL
`mJ6K&t$<
j>"@,B g*
public int getNSplitter() J<h$ wM
{ E4/Dr}4
return nSplitter; 2eY_%Y0
} flbd0NB
;$wVu|&
>SHhAEF
public void setNSplitter(int nCount) ul>3B4
{ ?1 4{J]H4
nSplitter = nCount; K Z91-
} n 0L^e
} S|N_o
})Vi
E*K;H8}s
/* _A9AEi'.
**Utility.java z46~@y%k
*/ d{3QP5
package NetFox; jm/`iXnMf
`1fY)d^ZS
e6$WQd`O
public class Utility { y_-0tI\J
o3P${Rq
h3 }OX{k
public Utility() ?%[@Qb=2
{ BW*rIn<?G
Lnl=.z`jK
T:yE(OBf
} Eo]xNn/g
v PG},m~-
//线程睡眠 4>e&f&y~
public static void sleep(int nSecond) +',S]Edx
{ y766; X:J
try{ =GMkR+<)
Thread.sleep(nSecond); .}~_a76
} v`Oc,
catch(Exception e) c,+:i1IAy
{ c 3)jccWTc
e.printStackTrace (); y}ev ,j
} c4eBt))}V
} T+H!_ky`A
.4!=p*Y
//日志 )zdQ1&@
public static void log(String sMsg) Bn&ze.F
{ cIOlhX@
System.err.println(sMsg); M!D3}JRm
} [/41%B2
/"Uqa,{
R8Fv{7]c
public static void log(int sMsg) =MDysb&:
{ ],Do6 @M-
System.err.println(sMsg); ope^~+c~\
} ~dTrf>R8M
} z_4J)?3
e8?jmN`2
@Z:l62l=bE
/* 6A+nS=
**TestMethod.java mtcw#D
*/ T!)(Dv8@F
package NetFox; {q^[a-h>
i2SR{e8:GF
H9Q&tl9
public class TestMethod { O5T{eBo\
p}U ~+:v
Yufc{M00
public TestMethod() $suzW;{#
{ ///xx/weblogic60b2_win.exe -;WGS o
try{ B>P{A7Q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }y gD3:vN7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tJ$_lk ~6q
SiteFileFetch fileFetch = new SiteFileFetch(bean); &E5g3lf
fileFetch.start(); 'c$+sp ?
} %YqEzlzF
catch(Exception e){e.printStackTrace ();} p947w,1![
N6i Q8P-
R%[ c;i
} ,/|T-Ka
m#\dSl}
bq0zxg%
public static void main(String[] args) UH"%N)[
{ Em~>9f ?Q(
new TestMethod(); }`m/bgtFX
} Ao&"r[oJSv
} YNsJZnGr8#
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