http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); !^&VZh
} 9:Oz-b
for(int i=0;i<nEndPos.length-1;i++) f}"eN/T
{ 3>^]r jFw
nEndPos = nStartPos[i+1]; Y!_{:2H8p
} PPH;'!>s"
nEndPos[nEndPos.length-1] = nFileLength; / Ws>;0
} Sc/l.]k+
} u*): D~A
W#~7X
kl]MP}wc
//启动子线程 h x&"fe
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )v_v 7 ~H&
for(int i=0;i<nStartPos.length;i++) ,}&TZkN{-
{ %4),P(4N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YI ?P@y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :;.^r,QAI
nStartPos,nEndPos,i); D\b$$z]q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y(bB7tR
fileSplitterFetch.start(); r'j88)^
} IHdA2d?.]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qv5fK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 38D5vT)n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E I(e3
nEndPos = " + nFileLength); n"T ^
// fileSplitterFetch[nPos.length-1].start(); tp}/>gU!
JJ7A` ;
9Y'pT.Gyb
//等待子线程结束 EW(bM^dk}
//int count = 0; RSh_~qMX
//是否结束while循环 vReX7
boolean breakWhile = false; N-?5[T"
+T@BOYhgq
D<d,9S,)
while(!bStop) 8 5X}CCQ
{ lUB?eQuN_
write_nPos(); rAfz?
Utility.sleep(500); u+r!;-0i
breakWhile = true; Ao8ua|:
-yBKA]"<I
&H%/.4la
for(int i=0;i<nStartPos.length;i++) l;0([_>*j
{ PXYLLX\3
if(!fileSplitterFetch.bDownOver) sWte&
{ Z::I3 Q
breakWhile = false; O&BvWik
break; 0S$k;q
} (&Rk#iU 2
} TLVsTM8P
if(breakWhile) t&?{+?p: 9
break; /]3[|
qWheoyAB
k\.9iI'6
//count++; 17Cb{Q
//if(count>4) uAeo&|&
// siteStop(); u6Gqg(7hw
} fV|uKs(W
Au'y(KB
;&O?4?@4
System.err.println("文件下载结束！"); p"p~Bx
} s{Qae=$Q
catch(Exception e){e.printStackTrace ();} h8asj0
} wpM2{NTP
wK-VA$;:
} 7 o!
//获得文件长度 uL^; i""
public long getFileSize() xj;:B( i
{ K<*6E@+i
int nFileLength = -1; {73V?#P4
try{ F1stRZ1ZI
URL url = new URL(siteInfoBean.getSSiteURL()); "ktuq\a@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I{cH$jt<
httpConnection.setRequestProperty("User-Agent","NetFox"); qx5`lm~L
i`2SebDj'w
c%/b*nQ(=
int responseCode=httpConnection.getResponseCode(); \L(cFjLIl
if(responseCode>=400) |qn2b=
{ C7ivAh
processErrorCode(responseCode); ]5"k%v|
return -2; //-2 represent access is error t<Yi!6
} BA:x*(%~
'c7nh{F
x^[,0?y2
String sHeader; 1OMXg=Y
Gy/w #4xj
"a)6g0gw
for(int i=1;;i++) " _2k3
{ y<Q"]H.CkQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w-pgtO|Us
//Utility.log(in.readLine()); ce\d35x!
sHeader=httpConnection.getHeaderFieldKey(i); !6'N-b1
if(sHeader!=null) Dhn7N8(LF!
{ 4-.K<-T%D
if(sHeader.equals("Content-Length")) b!@PS$BTxq
{ ^7spXfSAd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); HXa[0VOx
break; X>[i<ei
} (0NffM1
} mp8GHV
else "5V;~}=S
break; 60!%^O =
} _eiqs
} i7.8H*z'
catch(IOException e){e.printStackTrace ();} tRdf:F\X
catch(Exception e){e.printStackTrace ();} .U0Gm_c0
X!Z)V)@J8
{oqbV#/&
Utility.log(nFileLength); %42a>piev
%LMpErZO
&" t~d}Rg
return nFileLength; w.k9{f
} t<##0#xS.
FYYc+6n
T%eBgseS
//保存下载信息（文件指针位置） JI-i7P
private void write_nPos() cpjwc@UMe
{ H:c5 q0O^x
try{ 9i5?J]o^
output = new DataOutputStream(new FileOutputStream(tmpFile)); (lM,'
output.writeInt(nStartPos.length); X 61|:E
for(int i=0;i<nStartPos.length;i++) 9S|sTf
{ \ZLi Y
// output.writeLong(nPos); :0l+x0l}
output.writeLong(fileSplitterFetch.nStartPos); *2X~NJCt
output.writeLong(fileSplitterFetch.nEndPos); 3 ,>M-F
} $os]$5(
output.close(); ;Sivu-%
} %1Q:{m
catch(IOException e){e.printStackTrace ();} 0A)0Zw
catch(Exception e){e.printStackTrace ();} V8M()7uJ
} Qfm$q~`D^W
^Lgvey%
e-ta7R4
//读取保存的下载信息（文件指针位置） -"I$$C
private void read_nPos() jhm3:;Z
{ c#N4XsG,
try{ lr>NG,N
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f(|k0$EIu
int nCount = input.readInt(); [ey# ,&T
nStartPos = new long[nCount]; `MI;.t
nEndPos = new long[nCount]; Q ]CMm2L^f
for(int i=0;i<nStartPos.length;i++) @njNP^'Kx
{ "u^Erj# /
nStartPos = input.readLong(); Nu"v .]Y2
nEndPos = input.readLong(); |eu8;~A
} ytIPY7E
input.close(); oVpZR$
} WoZU} T-
catch(IOException e){e.printStackTrace ();} G]ek-[-
catch(Exception e){e.printStackTrace ();} j?N<40z
} Mr)t>4
h=A
"bhK%N;
private void processErrorCode(int nErrorCode) Nnh\FaI
{ NuQ!huh
System.err.println("Error Code : " + nErrorCode); s>J5.Z7"'j
} -MTk9<qnT
F$as#.7FF
X hq ss),
//停止文件下载 H@uu;:l<7A
public void siteStop() x2B8G;6u
{ ;|Mfq`s
bStop = true; WA(x]""
for(int i=0;i<nStartPos.length;i++) 0 %~~IT}U
fileSplitterFetch.splitterStop(); jB?SX
w.x&3aG
+|LM"
} 5C!zEI)
} ^N/d`IAjv
//负责部分文件的抓取 r ]7: ?ir
**FileSplitterFetch.java X9Ch(nWX
*/ :PT{>r[
package NetFox; =>;&M)+q
&4-;;h\H
8 MO-QO
import java.io.*; +F)-n2Bi
import java.net.*; ?9\D(V
/2? CB\
[on_=N{W[
public class FileSplitterFetch extends Thread { V5K/)\#
0>od1/`
'OA*aQ=K
String sURL; //File URL MrR`jXz
long nStartPos; //File Snippet Start Position B.; qvuM~
long nEndPos; //File Snippet End Position H'k}/<%Q
int nThreadID; //Thread's ID \n[kzi7
boolean bDownOver = false; //Downing is over VCWW(Y1Fd
boolean bStop = false; //Stop identical >aAM&4
FileAccessI fileAccessI = null; //File Access interface eNd&47lJ
qzZ/%{Ak
t<UJR*R=L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException V?M(exN
{ uY.Ns ?8
this.sURL = sURL; A08kwYxiW
this.nStartPos = nStart; X84T F~2Y
this.nEndPos = nEnd; =cEsv&i
nThreadID = id; 3mHzOs\jU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lOt7ij(,L
} }nlS&gew^
J%CCUl2
e\V -L_
public void run() a$=~1@
{ _Tj&gyS
while(nStartPos < nEndPos && !bStop) O>h`
{ 4Fft[S(
]Ucw&B*@
8* A%k1+
try{ v@=qVwX
URL url = new URL(sURL); /JS_gr@DK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S9Sgd&a9
httpConnection.setRequestProperty("User-Agent","NetFox"); P PJ^;s
String sProperty = "bytes="+nStartPos+"-"; Yj@Sy
httpConnection.setRequestProperty("RANGE",sProperty); Xfk DMh
Utility.log(sProperty); xh2r?K@k>
,m{R m0
i% 1UUI(W
InputStream input = httpConnection.getInputStream(); ^sf,mM~D
//logResponseHead(httpConnection); !5}}mf
lEHx/#qt9
iAz0 A
byte[] b = new byte[1024]; fmixWL7.Zg
int nRead; jfMkN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) qx ki
{ Cx2# 0$
nStartPos += fileAccessI.write(b,0,nRead); tczJk1g}
//if(nThreadID == 1) <iky~iE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /wLBmh1"
} x@OBGKV
rQ.zqr
o-=|}u]mz
Utility.log("Thread " + nThreadID + " is over!"); f8;?WSGyD2
bDownOver = true; }<^mUG
//nPos = fileAccessI.write (b,0,nRead); OInl?_,,T#
} (p5q MP]L
catch(Exception e){e.printStackTrace ();} b&P)J|Fe
} JQQ[jl;
} ,'0#q
$E@n;0P
&x1A{j_
//打印回应的头信息 c-k3<|H`
public void logResponseHead(HttpURLConnection con) P*6m~`"5
{ "OenYiz
for(int i=1;;i++) F1.Xk1y%
{ \ivxi<SR
String header=con.getHeaderFieldKey(i); 'V?FeWp
if(header!=null) 9qftMDLZJ\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -~]H5er`
Utility.log(header+" : "+con.getHeaderField(header)); Mc,|C)
else O.+J%],
break; ZPH_s^
} 2p&$bft
} @*y4uI6&
.aT@'a{F
r.eK;
public void splitterStop() dcY(1p)
{ D\THe-Vtr
bStop = true; H0s*Lb
} %'1iT!g8
KVOV<uDCj
m#UQ,EM
} Pdf-2 Tx
9K@I
&\9%;k
/* f- XUto
**FileAccess.java &<;T$Y
*//文件访问(定位，写) vqN/crJ@
package NetFox; DP@1to@
import java.io.*; /Z6lnm7wJ
B/;>v
n0lOq
public class FileAccessI implements Serializable{ Ca'BE#q
44u)F@)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 dNgA C){w
RandomAccessFile oSavedFile; +bE{g@%@+
long nPos; %4LoEm=U
c0zcR)=mL
(c[u_~ ;
public FileAccessI() throws IOException TX=894{nGh
{ _p6r5Y
this("",0); wnC} TWxX
} !An?<Sv$
fM ID}S
zb{79Os[B
public FileAccessI(String sName,long nPos) throws IOException A M[f
{ zd[k|lj
oSavedFile = new RandomAccessFile(sName,"rw"); 3JGrJ!x
this.nPos = nPos; NVx>^5QV
oSavedFile.seek(nPos); {N}az"T4f
} h\[@J rDa
`o{ Z;-OF
-|FHv+
public synchronized int write(byte[] b,int nStart,int nLen) JPZp*5c6A
{ iHhdoY[]
int n = -1; nook/7]
try{ :k_&Zd j,B
oSavedFile.write(b,nStart,nLen); C~T,[U
n = nLen; 4*}&nmW
} IVPN=jg?
catch(IOException e) q'8*bu_
{ Rj";?.R*e
e.printStackTrace (); @ ;!IPiU
} HX2u{2$
*F%1~
?^Aj\z>
return n; :2KHiT5
} RyK~"CWT
|p/*OFC6
y-26\eY^P
} l+6c|([
Z|C,HF+m.
)>1}I_1j)
/* +UDt2
**SiteInfoBean.java {`D]%eRO
*/ Gl>\p
package NetFox; D`@a*YIq
wKpBH}
Q$ew.h
public class SiteInfoBean { O(I^:_eH
Xr K29a
^<!R%"o-
private String sSiteURL; //Site's URL ULt5Zi
private String sFilePath; //Saved File's Path zH~P-MqC
private String sFileName; //Saved File's Name MJiVFfYW
private int nSplitter; //Count of Splited Downloading File 3g4=as4w
fJr EDj4(
Cdz?+hb
public SiteInfoBean() 0 8)f
{//nSplitter的缺省值为5 CaZc{
//default value of nSplitter is 5 1|{s8[;8
this("","","",5); ML>M:Ik+
} #;!@Pf
32K& IfV
z" tz-~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h)Fc<,vwBE
{ BX$<5S@
sSiteURL= sURL; "9P @bA
sFilePath = sPath; ^5s7mls
sFileName = sName; lOcFF0'
this.nSplitter = nSpiltter; 8?82 p
HK :K~h
lPR^~&/
} KS8@A/f
SY5}Bu#
(xW+* %
public String getSSiteURL() =u}~\ 'd
{ +A8q.-N G
return sSiteURL; .T7CMkYt
} 9xbT?$^
xy:Mb =r
FQ0&{ulb
public void setSSiteURL(String value) QD0x^v8
{ KWo Ps%G
sSiteURL = value; JE}VRMNr
} 5,,'hAq_
!@lx|=#
jv.tg,c_6
public String getSFilePath() BR|0uJ.M
{ ].rKfv:
return sFilePath; 5 <k)tF%
} w\i]z1
U3_O}X+
*eHa4I
public void setSFilePath(String value) |?J57(
{ <B>qEa_I
sFilePath = value; N4;g"k b
} ,j XK
O>~@>/#
Q>4NUq
public String getSFileName() 2&*#k
{ %ud-3u52M8
return sFileName; =iB[sLEJ
} kk`K;`[tB
k}:;`ST
Yr{hJGw[
public void setSFileName(String value) E+i(p+=4
{ 8SRUqe[H]
sFileName = value; fNi&r0/-t
} ,ASNa^7/>
4v>SXch
`^/8dIya
public int getNSplitter() 0?ab'vYcp
{ Jvc<j:{^w
return nSplitter; vWmp?m
} tW~kn9glZ
+pgHCzwJE
^[SW07o~
public void setNSplitter(int nCount) aPlEM_escS
{ !2Ompcr1
nSplitter = nCount; 1\,k^Je7
} Gjeb)Y6N
} g"" 1\rc=
MJX4;nbl
??aO3Vm{
/* QlvP[Jtr
**Utility.java BPv+gx(>k
*/ Q&PWW#D
package NetFox; @+t|Aa^g
6h5g!GQD
!i8)si_
public class Utility { qN1fWU#$
rD21:1s
ShL!7y*rT{
public Utility() F(.`@OO
{ oUsfO-dET^
7:F0?l*
EGI$=Y
} ZRYlm$C
YGPb8!
//线程睡眠 Zgh~7Z/
public static void sleep(int nSecond) " 4#&tNQ
{ .n+ ;&5
try{ GU`q^q@Ea
Thread.sleep(nSecond); ?i_/f}.K
} }Ifa5Lq)
catch(Exception e) p>pN?53S
{ '*XIp:
e.printStackTrace (); l?"^2in.
} nygGI_[l
} HD#>K 7
;39a`
//日志 zd2_k 9
public static void log(String sMsg) 0kCo0{+n
{ c;/vzIJj
System.err.println(sMsg); VF11eZ"
} :0(^^6Q\
7L/LlO/
3pML+Y|ij
public static void log(int sMsg) ShVR{gIs
{ Wn6m$=
System.err.println(sMsg); ]r!|@AWrQ\
} bBML +0a
} E> pr})^w
Z] r9lC
+JG05h%'
/* k@%5P-e}
**TestMethod.java $-]G6r
*/ .9Oj+:n
package NetFox; d, g~.iS~
Has}oe[
^L.I9a#]
public class TestMethod { 2HVqJib4Yn
03)irq%l;
rD$5]%Y
public TestMethod() kuBtPZ
{ ///xx/weblogic60b2_win.exe 2{WZ?H93a
try{ vv)w@A:Vn)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :RIqA/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v -)<nox
SiteFileFetch fileFetch = new SiteFileFetch(bean); <(TAA15Xol
fileFetch.start(); Ep;?%o,G
} 0LC]%x+"
catch(Exception e){e.printStackTrace ();} |O)ZjLx
B>'J5bZsw
mpD.x5jm<
} h`! 4`eI
GGwwdB\x'
Yur}<>`(
public static void main(String[] args) -">Tvi4
{ g qORE/[
new TestMethod(); dHOH]x
} o$->|k
} 8zRw\]?
点击下载更多相关资料