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)); rMDo5Z2
} Hya ";'
for(int i=0;i<nEndPos.length-1;i++) 5rG&Z5
{ R Wa4O#
nEndPos = nStartPos[i+1]; Y|ONCc
} u{%gB&nC
nEndPos[nEndPos.length-1] = nFileLength; Fv!zS.)`
} /8!s C D
} cG|)z<Z
\BB(0Ah+t
!3~VoNh,
//启动子线程 +rEqE/QF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -[-LR }u
for(int i=0;i<nStartPos.length;i++) |Ad1/>8i
{ Jvi"K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), YG2rJY+*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L #'N
nStartPos,nEndPos,i); :,.g_@wvG
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M6n9>aW4
fileSplitterFetch.start(); $lkd9r1
} x;H#-^LxW=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )h(Dt(2Wm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }7k!>+eQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g@WGd(o0)
nEndPos = " + nFileLength); a`}b'X:
// fileSplitterFetch[nPos.length-1].start(); >FtW~J"X
bkmW[w:M
h&|wqna
//等待子线程结束 }z/;^``
//int count = 0; 5+U2@XV
//是否结束while循环 6;/>asf
boolean breakWhile = false; ciKkazx.
+ -e8MvP
tPO\e]
while(!bStop) .E!p
{ ESOuDD2<
write_nPos(); <0[{Tn
Utility.sleep(500); ]:* 8 Mb#
breakWhile = true; n^QOGT.s6`
k;V4%O
{"33 .^=
for(int i=0;i<nStartPos.length;i++) Q;O\tl
{ by*>w/@9)k
if(!fileSplitterFetch.bDownOver) F?j;3@z[A
{ N*t91 X
breakWhile = false; r4Ygy/%
break; [BS3y`c
} XQEGMaZ
} LS:3Dtq
if(breakWhile) t3 AZS0
break; VdpkE0
YxMOr\B
Qy ; M:q
//count++; ?DVO\Cp
//if(count>4) lD09(|`
// siteStop(); 0x'-\)v>3
} i<D}"h|
a,Gd\.D
5,:tjn
System.err.println("文件下载结束！"); !O$*/7
} a!"81*&4#
catch(Exception e){e.printStackTrace ();} 66\0JsT?3
} #8;|_RU
{8M=[4_`l
s{q)m@
//获得文件长度 Z<a6U 3
public long getFileSize() NLDmZra
{ A.9,p
int nFileLength = -1; W>b(hVBE
try{ &]~z-0`$!
URL url = new URL(siteInfoBean.getSSiteURL()); }G&#pw2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); N"|^AF
httpConnection.setRequestProperty("User-Agent","NetFox"); &J|3uY,'j
3j.Ft*SV
&fYx0JT
int responseCode=httpConnection.getResponseCode(); b5YjhRimS
if(responseCode>=400) /'1UfjW>
{ qF6YH
processErrorCode(responseCode); b2 ~~!C
return -2; //-2 represent access is error fys@%PZq
} 8WWRKP1V
g~d}?B\<@
Egt;Bj#%
String sHeader; `gqBJi
9vL`|`Vau
ErF;5ec
for(int i=1;;i++) _<5o1
{ <\x/Y$jm0n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cHK)e2r
//Utility.log(in.readLine()); >HnD'y*
sHeader=httpConnection.getHeaderFieldKey(i); F#_7mC
if(sHeader!=null) JJ56d)37.
{ XF2u<sDe
if(sHeader.equals("Content-Length")) q`09
{ )8oI s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wgSA6mQZ
break; >]"5K<-1
} ~Dr/+h:^\
} c=H(*#
else VL"ZC:n)-
break; f+0dwlIlC$
} iR4CY-
} Ze~ a+%Sb
catch(IOException e){e.printStackTrace ();} 9QJ=?bIC#
catch(Exception e){e.printStackTrace ();} b@N|sXt&C
K&"Yv~h
mLD0Lu_Ob3
Utility.log(nFileLength); zsI0Q47\
:c,\8n
Rs)tf|`/
return nFileLength; =HP_IG_
} BZ1@?3
GQ&9by=}
3a#637%
//保存下载信息（文件指针位置） n4)G g~PE
private void write_nPos() #e&j]Q$Eh
{ N`y!Km
try{ \~xsBPX+x
output = new DataOutputStream(new FileOutputStream(tmpFile)); p<'mc|hGq
output.writeInt(nStartPos.length); H's67E/>*
for(int i=0;i<nStartPos.length;i++) -]5dD VSO
{ 8x'rNb
// output.writeLong(nPos); D>c%5h
output.writeLong(fileSplitterFetch.nStartPos); =(*Eh=Pw
output.writeLong(fileSplitterFetch.nEndPos); _h_;nS.Y
} 2Iz@lrO6
output.close(); yVQqz
} `a:@[0r0U
catch(IOException e){e.printStackTrace ();} 2U>1-p&dn
catch(Exception e){e.printStackTrace ();} iUA2/ A
} -9-%_=6
ZcX%:ebKS
$${ebt
//读取保存的下载信息（文件指针位置） %kNkDI
private void read_nPos() *ok89ad
{ ]V]~I.
try{ JU<<,0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ix^:qw;
int nCount = input.readInt(); yqlkf$?
nStartPos = new long[nCount]; u 8U>R=M
nEndPos = new long[nCount]; P%pB]d.qpi
for(int i=0;i<nStartPos.length;i++) gU>Y
{ a%ec: %
nStartPos = input.readLong(); 7H[#
nEndPos = input.readLong(); n5UcivyX
} (W3R3>;
input.close(); 3w{4G<I
} 0Qw?.#[9
catch(IOException e){e.printStackTrace ();} &4"(bZ:LO
catch(Exception e){e.printStackTrace ();} Q(AOKp,F
} 2b1LC!'U
<3HW!7Ad1
zDa*n:S
private void processErrorCode(int nErrorCode) XnWr~h{b
{ {FQ dDIj#
System.err.println("Error Code : " + nErrorCode); oX3Q9)
} `Lm ArW:
B_`A[0H
4OCz:t
//停止文件下载 LLgN%!&
public void siteStop() RZ|s[bU
{ @z dmB~C
bStop = true; $+JaEF`8
for(int i=0;i<nStartPos.length;i++) VbBZ\`b
fileSplitterFetch.splitterStop(); 5/:Zj,41{
8 gOK?>'9
Yl8tjq}iC
} 5[I> l
} jSVb5P
//负责部分文件的抓取 QwOQS %
**FileSplitterFetch.java 6JRee[
*/ /CKkT.Le
package NetFox; plfz)x3
X~GZI*P
&xH>U*c
import java.io.*; f=~@e#U
import java.net.*; BT d$n!'$n
j(nPWEyJM
+t.T+` EG
public class FileSplitterFetch extends Thread { 56?U4wj7{
gADt%K2#Z
$6fHY\i#R
String sURL; //File URL L=Dx$#|
long nStartPos; //File Snippet Start Position MrOW&7
long nEndPos; //File Snippet End Position *i5&x/ds
int nThreadID; //Thread's ID P|HY=RMa
boolean bDownOver = false; //Downing is over s_`wLQ7e
boolean bStop = false; //Stop identical 7jts;H=
FileAccessI fileAccessI = null; //File Access interface ( }JX ]-
22tY%Y9
U0jq.]P
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BAoqO Xv
{ 5Odi\SJ&
this.sURL = sURL; ODv)-J
this.nStartPos = nStart; n6Q 3X
this.nEndPos = nEnd; cY\-e?`=4
nThreadID = id; s)/i_Oe$\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .vpQ3m>
} n)`*{uv$
{j:{wW.
zb9d{e
public void run() 4D\_[(P
{ n=rPFpRLF
while(nStartPos < nEndPos && !bStop) *%Gy-5hM
{ /"iYEr%_
)E6m}?H5
MlRgdVX
try{ Mqw&%dz'_
URL url = new URL(sURL); \8Blq5n-O*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LfgR[!
httpConnection.setRequestProperty("User-Agent","NetFox"); dhm;
String sProperty = "bytes="+nStartPos+"-"; Q.\+ XR_|
httpConnection.setRequestProperty("RANGE",sProperty); xu+wi>Y^
Utility.log(sProperty); / d6mlQS
i7 p#%2
zac>tXU;
InputStream input = httpConnection.getInputStream(); 9SAyU%mS:
//logResponseHead(httpConnection); Pq7YJ"Z?:
C8&)-v|
@ULr)&9
byte[] b = new byte[1024]; Grjm9tbX}
int nRead; d8]6<\g
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6"_FjS3Sl
{ o`RTvGXk
nStartPos += fileAccessI.write(b,0,nRead); vj{h*~
//if(nThreadID == 1) Ap}:^k5{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p[Q
} *"9b?`E
%gw0^^A
NRoi` IIj
Utility.log("Thread " + nThreadID + " is over!"); {'d?vm!r
bDownOver = true; .P,\69g~A
//nPos = fileAccessI.write (b,0,nRead); W4>8
} GVEjB;
catch(Exception e){e.printStackTrace ();} I[[rVts
} ,T&B.'cq
} ?]3`WJOj
\n<N>j@3
gvy%`SSW
//打印回应的头信息 i$og v2J
public void logResponseHead(HttpURLConnection con) .4KXe"~E
{ Y=}b/[s6;
for(int i=1;;i++) t}'Oh}CG
{ [%QJ6
String header=con.getHeaderFieldKey(i); ;! CQFJ=
if(header!=null) kk!}mbA_}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2^qY,dL
Utility.log(header+" : "+con.getHeaderField(header)); y'4=
else Z#4? /'
break; _Dk;U*2
} ND21;
} kTC6fNj[
'>`bp25>
cm7aL%D$c
public void splitterStop() vhhsOga
{ ^$x^JM ]/
bStop = true; ~@sx}u
} +Do7rl
ze#LX4b I
<[a9"G7
} &p4q# p7,
>nl*aN
!vett4C* K
/* -{L[Wt{1
**FileAccess.java \>I&UFfH)4
*//文件访问(定位，写) )cOm\^,
package NetFox; 9B*SWWAj
import java.io.*; 4H1s"mP<
b(~NqV!i
L"('gc!W
public class FileAccessI implements Serializable{ gL}K84T$S
LClPAbr
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?}lCS7&
RandomAccessFile oSavedFile; ]qv/+~Qs>
long nPos; AK[9fxrE
ADHe![6q
uMqo)J@s
public FileAccessI() throws IOException jRq>Sz{8
{ "=/XIM.
this("",0); '-ACNgNn
} dks0
J-I7K!B
L'['7
public FileAccessI(String sName,long nPos) throws IOException dmE-WS
{ W:0@m^r
oSavedFile = new RandomAccessFile(sName,"rw"); Txw,B2e)>
this.nPos = nPos; M{z+=c&w
oSavedFile.seek(nPos); *M KVm)Iv
} {d7KJmN
0HG*KW
e@X~F6nP
public synchronized int write(byte[] b,int nStart,int nLen) O'5(L9,
{ E[_Z%zd^
int n = -1; <pPI:D@G
try{ P^1rNB
oSavedFile.write(b,nStart,nLen); r*,]=M W
n = nLen; `CHgTkv
} 1S_KX.
catch(IOException e) lYy0
{ ]bS\*q0Zf(
e.printStackTrace (); nC`=quM9
} }25{"R}K
)EcF[aO
$'[( DwLS
return n; kv5D=0r
} $RF"m"
L!e@T'
78NAcP~6c
} "w_(p|cm=
TJO|{Lxm
u`
/* v8wN2[fC
**SiteInfoBean.java d5WE^H)E.
*/ I#9K/[
package NetFox; =#>P!
qLPI^g,
lkl#AH
public class SiteInfoBean { ,cbP yg
2poU\|H
_ k>j?j-
private String sSiteURL; //Site's URL /?by4v73P
private String sFilePath; //Saved File's Path A 7TP1
private String sFileName; //Saved File's Name 3HfT9
private int nSplitter; //Count of Splited Downloading File 2@A7i<p
;N4mR6
wV(_=LF
public SiteInfoBean() n}._Nb 5
{//nSplitter的缺省值为5 9Uk9TG5
//default value of nSplitter is 5 V#sANi?mpo
this("","","",5); +/UInAM
} Ya,>E@oc
oTfEX4 t {
%7L'2/Y2x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~}TVM%0RTq
{ 57r\s8
sSiteURL= sURL; ?DpMR/
sFilePath = sPath; +LX&1GX
sFileName = sName; ok[R`99
this.nSplitter = nSpiltter; 4#=^YuKaF1
9^jO^[>
q 2=^l
} oR3$A :!P=
`#9ZP
UkeW2l`:
public String getSSiteURL() >Axe7<l
{ i>0bI^H
return sSiteURL; XSZW9/I-(|
} vbA9V<c&
Be}Cj(C
irrQ$N}
public void setSSiteURL(String value) f)gA.Rz
{ sy]1Ba%
sSiteURL = value; KXR
} beO*|
I-+D+DhRx
WxIP~
public String getSFilePath() !q$IB?8
{ ~IlgcCF
return sFilePath; McA,
} WI~';dK2]
w`i3B@w
|E!xt6B
public void setSFilePath(String value) a:@Eg;aN*O
{ 3pl.<;9r
sFilePath = value; ^8We}bs-c
} Z;Tjjws
4J_18.JHP
h`jtmhoz
public String getSFileName() ,wnF]K2D0
{ Ak|jJ
return sFileName; 3B;B#0g50
} |ss_<
QvqX3FU
v`nodI
public void setSFileName(String value) T#h`BtET[
{ "9R3S[
sFileName = value; tohYwXN
} QDSB <0j
2uqdx'^"
F#W'>WBU
public int getNSplitter() ~EdmVEu
{ +/AW6
return nSplitter; 80 p7+W2m
} 6``!DMDt/P
YZ'gd10T
P^.L0T5g
public void setNSplitter(int nCount) oSTGs@EK
{ lgre@M]mg
nSplitter = nCount; ~0ZP%1.B3
} B&<Z#C:I
} 8<IOX
{wCQ#V
;Wb W\,P'
/* ? NVN&zD]
**Utility.java pGUrYik4
*/ C2bN<K
package NetFox; W!+5}\?
L# (o(4g2
G9^!= v@
public class Utility { X@jml$;$
lwjg57
Jfo#IRC
public Utility() *`mwm:4
{ C#vU'RNpl
uiO8F*,!&r
q[**i[+%
} XCQ=`3f
LLV:E{`p
//线程睡眠 <C]s\"o-`
public static void sleep(int nSecond) :8\z 0
{ 6fQQKM@a|
try{ vvdC.4O
Thread.sleep(nSecond); 7e>n{rl
} r!j_KiUy
catch(Exception e) ~eE2!/%9
{ z l@ <X0q
e.printStackTrace (); {n2jAR9nq
} |)yO]pB:
} f~8Xue,l"
>`\~=ivrD
//日志 62a{Ggs{
public static void log(String sMsg) iv:[]o
{ B-'Xk{
System.err.println(sMsg); t"JfqD E
} qp'HRh@P2:
K^?/
W 4~a`D7
public static void log(int sMsg) n:Ka@
{ 29 ')Y|$,
System.err.println(sMsg); Lk=f^qJ ]
} E*j)gj9
} n1!0KOu/N
pz#oRuujY
CGny#Vh
/* 'I\bz;VT
**TestMethod.java '+5*ajP<
*/ d5UdRX]*
package NetFox; 9xN4\y6F
1Ep!U#Del
U''/y\Z
public class TestMethod { mGwBbY+5n
7WKb| /#;
dI{)^
public TestMethod() K'Bq@6@C g
{ ///xx/weblogic60b2_win.exe h@@2vs2
try{ D3|y|Dr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @e3O=_m-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8v5cQ5Lc
SiteFileFetch fileFetch = new SiteFileFetch(bean); ##EMJi
fileFetch.start(); [f&ja[m q
} ~UEft
catch(Exception e){e.printStackTrace ();} ^4h/6^b0c
<jY"+@rF
bK<'J=#1
} Mb"i}Yt{
J*5)g
m ['UV2
public static void main(String[] args) \Om.pOz
{ yiWBIJ2Wu9
new TestMethod(); r`HtN{6r
} $0+AR)
} {D 9m//x
点击下载更多相关资料