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)); {d.z/Buu
} KVOV<uDCj
for(int i=0;i<nEndPos.length-1;i++) 4G,FJjE`p
{ 2 q4p-
nEndPos = nStartPos[i+1]; @mCe{r*`
} 6=/sEzS'
nEndPos[nEndPos.length-1] = nFileLength; f- XUto
} )7 Mss/2T
} HS<Jp44
)Jjp^U3Ub
PgA<pfEHE
//启动子线程 7*PBJt\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &za }THm
for(int i=0;i<nStartPos.length;i++) v/ N[)<
{ Ro]Z9C>1o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Yk|6?e{+)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), sbmtx/%U
nStartPos,nEndPos,i); +bE{g@%@+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WJD2(el
fileSplitterFetch.start(); 1\fx57a\
} )YAa7\Od
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }>6e-]MHfR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rC!O}(4t%$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VFf;|PHS
nEndPos = " + nFileLength); M)#9Q=<
// fileSplitterFetch[nPos.length-1].start(); \}Am]Y/ w
OWibmX
684& H8
//等待子线程结束 >pp/4Ia!
//int count = 0; zd[k|lj
//是否结束while循环 C>Hdp_Lm
boolean breakWhile = false; i6WPf:#wr
rp4D_80q
@/^<9
while(!bStop) 8r(awp
{ "Ol:ni1
write_nPos(); B{)#A?Rh.
Utility.sleep(500); 7"'RE95
breakWhile = true; >UCg3uFj
TnN ythwZ
nook/7]
for(int i=0;i<nStartPos.length;i++) OdFF)-K>~
{ nms[No?
if(!fileSplitterFetch.bDownOver) (B4)L%
{ j;`pAN('
breakWhile = false; 5@xR`g-
break; oT\K P
} "d)YqQ
} K@7%i|H
if(breakWhile) )zxb]Pg+
break; c[ZrQJ
[e` |<
2VY7?1Ab(@
//count++; O8 .iP+
//if(count>4) =H)]HxEEM
// siteStop(); d'96$e o~
} trDw|WA
O5r8Ghf)
[ iTP:8
System.err.println("文件下载结束！"); `o#(YEu
} inU5eronuj
catch(Exception e){e.printStackTrace ();} 8e-nzc,]
} A8.noV
+UDt2
%"v:x?d$$o
//获得文件长度 sY!JB7!j
public long getFileSize() Ypzmc$Xfu
{ p(pfJ^/:(
int nFileLength = -1; 8vuTF*{yZ
try{ S%MDQTM
URL url = new URL(siteInfoBean.getSSiteURL()); c~tl0XU1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rhkKK_
httpConnection.setRequestProperty("User-Agent","NetFox"); |Lg2;P7\
MZ}0.KmaZ
6agq^wI
int responseCode=httpConnection.getResponseCode(); =W7-;&
if(responseCode>=400) I-^sJ@V;
{ oZ*?Uh*
processErrorCode(responseCode); 3*I\#Z4p1
return -2; //-2 represent access is error ^gcB+
} bdWdvd:
48wt
W7n^]~V
String sHeader; ta{24{?M\
eOb--@~8
]<<,{IQ
for(int i=1;;i++) v'?Smd1v /
{ <5G(Y#s/?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )f$4:Pq
//Utility.log(in.readLine()); L6CI9C;-b
sHeader=httpConnection.getHeaderFieldKey(i); UdrgUqq)
if(sHeader!=null) !(q@sw(
{ KyrZ&E.`
if(sHeader.equals("Content-Length")) A@>/PB6n
{ 9.(|ri
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,+df=>$W
break; AM=,:k$
} Y0g]-B
} oIO@#
else _OG9wi(Fpx
break; )yyH_Ax2
} 02Vfg42
} a2.6S./
catch(IOException e){e.printStackTrace ();} =l:V9u-I^
catch(Exception e){e.printStackTrace ();} ?Ojv<L-f.:
a!bW^?PcK
U Y*`R
Utility.log(nFileLength); BR|0uJ.M
].rKfv:
j-BNHX
return nFileLength; JL G!;sov
} .I~:j`K6
WA2NjxYz
s3sRMB2
//保存下载信息（文件指针位置） \2;!}
private void write_nPos() N4;g"k b
{ ,j XK
try{ %P~;>4i,
output = new DataOutputStream(new FileOutputStream(tmpFile)); |aenQA#
output.writeInt(nStartPos.length); d,?D '/
for(int i=0;i<nStartPos.length;i++) )A*53>JV
{ =7e!'cF[
// output.writeLong(nPos); Ze>R@rK
output.writeLong(fileSplitterFetch.nStartPos); P Ptmh. }e
output.writeLong(fileSplitterFetch.nEndPos); zwC ,,U
} 5{(4%
output.close(); &S xF"pYV
} Zq&'a_
catch(IOException e){e.printStackTrace ();} fNi&r0/-t
catch(Exception e){e.printStackTrace ();} ,ASNa^7/>
} v76P?[
gw"SKp!]
d;>G
//读取保存的下载信息（文件指针位置） 47(_5PFb#
private void read_nPos() odca?
{ Ud+,/pE>FA
try{ /1Gmga5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m19\H
int nCount = input.readInt(); c/88|k
nStartPos = new long[nCount]; W#!AZ!
nEndPos = new long[nCount]; WYF8?1dt +
for(int i=0;i<nStartPos.length;i++) w/ ~\NI
{ ;+C$EJw-
nStartPos = input.readLong(); d1_kw A2y
nEndPos = input.readLong(); (b~l.@xh
} ??aO3Vm{
input.close(); QlvP[Jtr
} I(7GVYM
catch(IOException e){e.printStackTrace ();} Pqx?0f)
catch(Exception e){e.printStackTrace ();} 4z P"h0
} mfg>69,w
W*s=No3C
P !f{U;B
private void processErrorCode(int nErrorCode) ?,7!kTRH
{ Es#:0KH].v
System.err.println("Error Code : " + nErrorCode); ]v}W9{sY
} vfn[&WN]
o:v_I{
!S&/Zp
//停止文件下载 NV?x<LNWd
public void siteStop() e46`"}r
{ |pZ7k#%
bStop = true; |BM#rfQ
for(int i=0;i<nStartPos.length;i++) rAtCG1Vr
fileSplitterFetch.splitterStop(); .n+ ;&5
w=?nD6Xhz
kwaZn~
} p>pN?53S
} l?"^2in.
//负责部分文件的抓取 sg-^ oy*^
**FileSplitterFetch.java /-!Fr:Ox>
*/ evZP*N~G
package NetFox; p#w8$Qjp
l"JM%LV
@ NDcO,]
import java.io.*; K:-jn}i?/
import java.net.*; ~D5FnN9
{hN\=_6*EW
m4h)Wq
public class FileSplitterFetch extends Thread { M 2| k.
b=S"o )>
zQ:nL*X'Z"
String sURL; //File URL &a'mG=(K_c
long nStartPos; //File Snippet Start Position p:b{>lM
long nEndPos; //File Snippet End Position qF^P\cD
int nThreadID; //Thread's ID +JG05h%'
boolean bDownOver = false; //Downing is over k@%5P-e}
boolean bStop = false; //Stop identical $-]G6r
FileAccessI fileAccessI = null; //File Access interface k(tB+k!vH\
!21G$[H
(rJ-S"^u
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3}g>/F~
{ 6d8)]
this.sURL = sURL; L"vk ^>E6
this.nStartPos = nStart; N/WtQSl
this.nEndPos = nEnd; }@6yROy.
nThreadID = id; Q)4[zStR#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QZ(O2!Mg
} NG3:=
QqF*SaO>
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public void run() }\H. G
{ SJ22
while(nStartPos < nEndPos && !bStop) cM9>V2:P
{ %4rlB$x
xe6V7Wi/Tt
x])j]k
try{ uL7}JQ,
URL url = new URL(sURL); Yur}<>`(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D@sMCR
httpConnection.setRequestProperty("User-Agent","NetFox"); n%\\1
String sProperty = "bytes="+nStartPos+"-"; $#/8l58
httpConnection.setRequestProperty("RANGE",sProperty); Fv,c8f
Utility.log(sProperty); E$8-8[
+W1l9n*
dk1q9Tx
InputStream input = httpConnection.getInputStream(); nTsV>lQY,
//logResponseHead(httpConnection); WxD$k3U
r9(c<E?,h
ER-Xd9R
byte[] b = new byte[1024]; 3ONWu
int nRead; i@P=*lLD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HQ=pf >
{ ZTqt4H
nStartPos += fileAccessI.write(b,0,nRead); xzz@Wc^_
//if(nThreadID == 1) M@q)\UQ'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IeChz d
} ,1|=_M31
;7E"@b,tPN
G,Yctv
Utility.log("Thread " + nThreadID + " is over!"); MW^FY4V1m
bDownOver = true; QHje}
//nPos = fileAccessI.write (b,0,nRead); Q ijO%)
} Qu<HeSA_
catch(Exception e){e.printStackTrace ();} t3}_mJ
} #,lbM%a
} \QSD*
~ cu+QR)
( Ygy%O%
//打印回应的头信息 %NlmLWF.
public void logResponseHead(HttpURLConnection con) >~_>.R+{
{ N0D5N(kH%
for(int i=1;;i++) N{RHbSa(
{ nWYfe-zQxg
String header=con.getHeaderFieldKey(i); FB+nN5D/
if(header!=null) nf_(_O=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v(sS$2J|}
Utility.log(header+" : "+con.getHeaderField(header)); ?JRfhJ:j
else 4u|6^wu.I
break; >4>. Ycp
} [KO\!u|?YS
} |%X_<Cpk
ss|n7
xXV15%&
public void splitterStop() b0%#=KMi
{ @$QtY(a
bStop = true; EG=U](8T
} },5LrX`L
R 'mlKe x
W^:g_
} 6xh-m
XxB%
|QH )A
/* z}VCiS0
**FileAccess.java B%[#["Ol
*//文件访问(定位，写) +C`vO5\0
package NetFox; {iLr$89
import java.io.*; RKs_k`N0
}?GeU Xhy
/xA`VyHO
public class FileAccessI implements Serializable{ aC'#H8e|j
CS"k0V44}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1*@Q~f:Uk
RandomAccessFile oSavedFile; G in
long nPos; \=W t{
{2|sk9?W
5=MM^$QG
public FileAccessI() throws IOException oFGgr2Re
{ :SD3
this("",0); eLN(NSPoS
} xdsF! Zb
q=BAYZ\`
P/9|mYmsq
public FileAccessI(String sName,long nPos) throws IOException kA4kQ}q
{ #DTBdBh?I
oSavedFile = new RandomAccessFile(sName,"rw"); EX3;|z@5;
this.nPos = nPos; 'aZAWY d
oSavedFile.seek(nPos); 97!VH>MX
} 5i3nz=~o
T:j!a{_|
pHDPj,lu
public synchronized int write(byte[] b,int nStart,int nLen) uUpOa+t
{ ~65lDFY/
int n = -1; ]7dal [i
try{ \l;H!y[
oSavedFile.write(b,nStart,nLen); D>q?My
n = nLen; [;INVUwG^
} MES|iB
catch(IOException e) I1Gk^wO
{ 0jefV*3qpB
e.printStackTrace (); '-X913eG!
} j7&0ckN&G
e-{4qt
BA0.B0+"
return n; V:4($
} ZZ;V5o6E
o|a]Q
n)teX.ck)
} A832z`
pK2n'4 C
_UeIzdV9
/* !}uev
**SiteInfoBean.java ;,_c1x/F
*/ ?jBh=X\]:
package NetFox; POUD*(DqNK
9o5_QnGE
y {1p#
public class SiteInfoBean { nxYp9,c"
$3n@2 N`
(kI@U![u
private String sSiteURL; //Site's URL kIUb`b>B
private String sFilePath; //Saved File's Path .hXdXY
private String sFileName; //Saved File's Name d5B96;3
private int nSplitter; //Count of Splited Downloading File _9zydtw
u%Yr&u
]O;Rzq{D(
public SiteInfoBean() )%5T*}j
{//nSplitter的缺省值为5 s*pgR=dZZ
//default value of nSplitter is 5 "Q@ZS2;A
this("","","",5); !tD,phca~
} 4mzWNr>fb
7_#i,|]58
=i)k@w_(x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7^:0?Q
{ 3~!PJI1
sSiteURL= sURL; R'r^v
sFilePath = sPath; \=/^H
sFileName = sName; Me*]Bh
this.nSplitter = nSpiltter; ,
XmoS$/#"
%sLij*
} APksY!
o93A:fc
3$`qy|=zO
public String getSSiteURL() wMB<^zZmv
{ f)+fdc
return sSiteURL; ojH-;|f
} ~FV Z0%+,
i;>Hy|
vb.`rj6
public void setSSiteURL(String value) _,4f z(
{ f[/E $r99J
sSiteURL = value; #_bSWV4
} uU]4)Hp
S)*eAON9
Qy@r&
public String getSFilePath() )#dP:
{ ^25[%aJI
return sFilePath; ?qQRA|n*
} Y<S,Xr;J:
@kLpK
`QlChxd
public void setSFilePath(String value) 0 .dSP$e
{ r`L$[C5I
sFilePath = value; )LwB
} Mc6?]wDB]
a{6rQ
c.PPVqx
public String getSFileName() ^kMgjS}R
{ F+S;u=CKx
return sFileName; i-E~ZfJ
} %!HmtpS
DPNUm<>
XoaBX2
public void setSFileName(String value) f&Bu_r
{ of^N4
sFileName = value; ; . c]0
} bd2"k;H<o
`1KZ14K
;o#R(m@Lx
public int getNSplitter() eRa1eRgP
{ zRJopcE<
return nSplitter; :R<n{%~
} yl%F}kBR
56m|gZcC
$vdGkz@6
public void setNSplitter(int nCount) @"H+QVJ@
{ P~:W+!@5v
nSplitter = nCount; ht S5<+Y
} m(8t |~S
} @fbB3
% ;2x.
Nze#u;
/* {q"l|Oe
**Utility.java E#T-2^nD
*/ S3Tww]q
package NetFox; AtA}OY]D/
lV^sVN Z]
2Fce| Tn
public class Utility { It4J\S
Kl$!_$
s"G6aM
public Utility() ^=wG#!#V"1
{ ~OEP)c\k
vGC^1AM
#uT-_L}sw
} $_l@k=
0bpl3Fh.v
//线程睡眠 Db= iJ68
public static void sleep(int nSecond) ZSMOq4Y 9
{ %u43Pj
try{ >"S'R9t
Thread.sleep(nSecond); `{/z\
} LeY\{w
catch(Exception e) HT5G HkT
{ ])a?ri
e.printStackTrace (); ]RQQg,|D
} V2'(}k
} #T n~hnW
^c^9kK'
//日志 BRV /7ao="
public static void log(String sMsg) t}`|\*a
{ ]`y4n=L.
System.err.println(sMsg); Kig.hHj@
} HlY4%M5q/
rsvZi1N4w$
o_EXbS]C
public static void log(int sMsg) } CJQC
{ d"nE+pgE
System.err.println(sMsg); O.1Z3~r-N
} w-|i8%X
} aIZ@5w"7
z8= Gc$w!
&|26x >
/* Om{[ <tL
**TestMethod.java ![:S~x1
*/ 3`k1
package NetFox; 5 8p_b
ALwkX"AN
*n2Q_o
public class TestMethod { yIbz\3
M0x5s@
F)Yn1&a#H
public TestMethod() W==HV0n
{ ///xx/weblogic60b2_win.exe bUp%87<*X
try{ n\.K:t[:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =M7FD
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7vcYI#(2 Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); JHc|.2Oe
fileFetch.start(); @ MNL
} )-[ 2vhXz
catch(Exception e){e.printStackTrace ();} yK0Q,
EUe2<G
D_9&=aa'
} pR&cdORsP
3.Qf^p
~7b'4\
public static void main(String[] args) s+tS4E?
{ C%"h1zWE:
new TestMethod(); o~gduNG#
} rr*",a"}m
} @|%t<{y^I
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