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)); bK%go
} M6!kn~
for(int i=0;i<nEndPos.length-1;i++) 3vOI=ar=L~
{ <27B*C M
nEndPos = nStartPos[i+1]; )F<<M+q=
} r3w.$
nEndPos[nEndPos.length-1] = nFileLength; C4Q^WU+$j
} _3T*[s;H
} #l-,2C~
2?ZHWS>U
7(~^6Ql!
//启动子线程 ZzI^*Nyg
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E[LXZh
for(int i=0;i<nStartPos.length;i++) Y_%\kM?7
{ YjS|Ht->
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Lq LciD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), U%_a@&<
nStartPos,nEndPos,i); .gT@_.ZD9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n=t%,[Op
fileSplitterFetch.start(); b_Ba0h=
} hS +;HB,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lyZof_/*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "=|yM~V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *D;B%j^;
nEndPos = " + nFileLength); <g,k[
// fileSplitterFetch[nPos.length-1].start(); d2.eDEOsC
Dw[w%uz
vD1jxk'fd
//等待子线程结束 >6ch[W5k@
//int count = 0; pq-zy6^
//是否结束while循环 f|6%71
boolean breakWhile = false; =q[3/'2V$?
I U4[}x
~v,LFIT
while(!bStop) V%ykHo
{ ]pb;q(?^
write_nPos(); sTv/;*
Utility.sleep(500); q.<q(r
breakWhile = true; Ylt[Ks<2
P]x@h
NCsUC
for(int i=0;i<nStartPos.length;i++) +X- k)9
{ "?il07+w%
if(!fileSplitterFetch.bDownOver) *V\kS
{ bH.">IV
breakWhile = false; EHb:(|UA%8
break; o60wB-y
} `BvcIn4do
} -OHG1"/
if(breakWhile) *83+!DV|
break; ?+!KucTF
b6i0_fOO
RHBEC@d[}
//count++; hN}X11
//if(count>4) o+vf
// siteStop(); $M8'm1R9
} (0][hdI~B
UFl*^j_)]
+:t1PV;l
System.err.println("文件下载结束！"); Y'Af I^K
} a[u8x mH
catch(Exception e){e.printStackTrace ();} f+1]#"9i|
} \i&yR]LF
`b2I)xC#
(&B & V
//获得文件长度 LY|h*a6Ym
public long getFileSize() B|%;(bM2C
{ tQ/w\6{
int nFileLength = -1; QVP $e`4
try{ Wm A:"!~M
URL url = new URL(siteInfoBean.getSSiteURL()); z#\Z|OKU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hZFbiGQr\
httpConnection.setRequestProperty("User-Agent","NetFox"); ecFI"g
igp4[Hj
"<&F=gV
int responseCode=httpConnection.getResponseCode(); o#T,vu0s
if(responseCode>=400) &3JbAJ|;X
{ _ 9k^Hd[L$
processErrorCode(responseCode); -1{N#c/U
return -2; //-2 represent access is error 8'?e4;O
} /Ly%-py-$
-ZuzJAA
v-l):TL+=
String sHeader; (zhmZm
NLdUe32A
)sL:iGU
for(int i=1;;i++) Y3-P*
{ X+*| nvq]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); mr/^lnO
//Utility.log(in.readLine()); `$i`i'S
sHeader=httpConnection.getHeaderFieldKey(i); $$8"i+,K
if(sHeader!=null) T&!>lqU!J
{ GJW1|Fk
if(sHeader.equals("Content-Length")) MLR3A s
{ +28FB[W
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bb1dH/8
break; $zdJ\UX
} ypml22)kz
} Ck[Z(=b$$:
else 8RocObY_W
break; 7?kvrIuY&
} c\R!z&y~
} >#V8l@IH
catch(IOException e){e.printStackTrace ();} PL VF
catch(Exception e){e.printStackTrace ();} ]`|bf2*eA
#!5GGe{I
Pajr`gU
Utility.log(nFileLength); is`a_{5e=
=g&0CFF<
]])i"oew
return nFileLength; $D45X<
} fCTjTlh
ZLO_5#<
hup]Jk
//保存下载信息（文件指针位置） 7#<|``]zNf
private void write_nPos() 7u!p.kN
{ |_ ;-~bmb
try{ CqF< BE
output = new DataOutputStream(new FileOutputStream(tmpFile)); @4&sL](q
output.writeInt(nStartPos.length); QALMF rWH
for(int i=0;i<nStartPos.length;i++) 6%5A&&O(b
{ LxG :?=O.
// output.writeLong(nPos); *FqNzly
output.writeLong(fileSplitterFetch.nStartPos); x-q er-
output.writeLong(fileSplitterFetch.nEndPos); @@! R Iq!
} }]f)Fz
output.close(); j7i[z>:Y
} TeG'cKz
catch(IOException e){e.printStackTrace ();} M.t5,NJ
catch(Exception e){e.printStackTrace ();} rb9x||
} {9)LHX7dN
R(hqBa/V
6C
//读取保存的下载信息（文件指针位置） xo?f90+(
private void read_nPos() 8rw;Yo<k
{ 2O4UytN
try{ e+2!)w)[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z|3l2ucl
int nCount = input.readInt(); R*QL6t
nStartPos = new long[nCount]; in%+)`'nH7
nEndPos = new long[nCount]; lKe aI
for(int i=0;i<nStartPos.length;i++) D3MuP p-v
{ :JPI#zZun
nStartPos = input.readLong(); "ua/65cq9
nEndPos = input.readLong(); |~'{ [?a*
} k:af
input.close(); ZfMJU
} Y5(`/
catch(IOException e){e.printStackTrace ();} kigc+R
catch(Exception e){e.printStackTrace ();} G*Qk9bk9
} ^@jOS{f l
O8n\>pkI
MNkysB(
private void processErrorCode(int nErrorCode) FWPkvL
{ kg+"Ta[9
System.err.println("Error Code : " + nErrorCode); ^d-`?zb
} ~pwp B2c
`P"-9Ue=
O!uX:TE|Q
//停止文件下载 &eyFApM[Z
public void siteStop() )%WS(S>8
{ !d%OoRSU'
bStop = true; HL*jRl
for(int i=0;i<nStartPos.length;i++) %p@A8'b
fileSplitterFetch.splitterStop(); tUL(1:-C
;nSaZ$`5
Ewu 7tq Z
} 4*d_2:|u
} ;k!bv|>n
//负责部分文件的抓取 efRa|7!HK
**FileSplitterFetch.java "X"DTP1b
*/ Vh4z+JOC
package NetFox; W<v?D6dFq
Up)b;wR
WWHT;ST
import java.io.*; \MX>=
import java.net.*; \S1WF?<,
;./Tv84I^
GS\-
public class FileSplitterFetch extends Thread { y}nM'$p
dt^yEapjM
i#&]{]}Qv
String sURL; //File URL %GjF;dJ
long nStartPos; //File Snippet Start Position =i\~][-
long nEndPos; //File Snippet End Position >"N\ZC^
int nThreadID; //Thread's ID e2k!5OS
boolean bDownOver = false; //Downing is over s%;18V:pi
boolean bStop = false; //Stop identical phEM1",4T
FileAccessI fileAccessI = null; //File Access interface %\Ig{Rj;
5|wQeosXxI
'+Ts IJh
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +#,t
{ $l-j(=Md
this.sURL = sURL; |]Pigi7y-
this.nStartPos = nStart; o7&Z4(V
this.nEndPos = nEnd; .V 9E@_(
nThreadID = id; V=QvwQlZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,|?B5n&
} ?r2Im5N
R qOEQ*k
x]Q+M2g?
public void run() ]%"Z[R
{ FzFY2h;n]B
while(nStartPos < nEndPos && !bStop) 'R,1Jmx
{ dD@T}^j *|
#oJ9BgDry
6TlkPM$~2
try{ /N{xFt/?
URL url = new URL(sURL); +q1 @8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oRmN|d ~4
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Q-kD?PO,
String sProperty = "bytes="+nStartPos+"-"; %l5Uy??Z
httpConnection.setRequestProperty("RANGE",sProperty); _+.z2} M
Utility.log(sProperty); \7jcZ~FBX%
/'!F \ kz
u`R
InputStream input = httpConnection.getInputStream(); oC^-" (#
//logResponseHead(httpConnection); ^A;v|U
|!flR? OU
|JnJ=@-y
byte[] b = new byte[1024]; _N.ZpKVu
int nRead; z*I=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OAc+LdT
{ UXR$7<D+
nStartPos += fileAccessI.write(b,0,nRead); C(xdiQJh
//if(nThreadID == 1) cuW$%$F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,.x1+9X
} kYmkKl_
ft?J|AG
[gqV}Y"Md
Utility.log("Thread " + nThreadID + " is over!"); Q<wrO
bDownOver = true; 6]CY[qEaR$
//nPos = fileAccessI.write (b,0,nRead); Y GvtG U-
} xzAyE5GL>
catch(Exception e){e.printStackTrace ();} G\ru%
} k 32Jz.\B
} '<4/Md[
Aum&U){yY
sMs 0*B-[
//打印回应的头信息 _~-VH&g0R
public void logResponseHead(HttpURLConnection con) cRI&cN"o
{ u\Tq5PYXt
for(int i=1;;i++) u01x}Ff~6
{ #L`@["
String header=con.getHeaderFieldKey(i); OF2*zU7M
if(header!=null) [?.k8;k
//responseHeaders.put(header,httpConnection.getHeaderField(header)); P!0uAkt9C
Utility.log(header+" : "+con.getHeaderField(header)); +YI/(ko=
else UQ}[2x(Kb
break; 9i;%(b{
} B8:G1r5G/
} m6a`OkP
onI%Jl sq
-r@fLkwg
public void splitterStop() *:{s|18Pj
{ mCb(B48]%X
bStop = true; iqreIMWz
} nm`[\3R
;6KcX\g-
%@k@tD6
} ? %XTD39
W8z4<o[$
>E;kM B
/* <2"'R(4",
**FileAccess.java MKf|(6;~
*//文件访问(定位，写) 7 XE&[o
package NetFox; )CJXkzOX
import java.io.*; ,R#pQ 4
:tBIo7
lR5[UKr
public class FileAccessI implements Serializable{ 8eq*q
2[ = =
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~"|MwR!0
RandomAccessFile oSavedFile; kl%%b"h'
long nPos; : fMQ,S0
E6JfSH#
C@d*t?
public FileAccessI() throws IOException ~tx|C3A`d
{ cq+G0F+H
this("",0); iZY4+ X
} !l NCuR/T
mh#NmW>n
~wYGTm=(n
public FileAccessI(String sName,long nPos) throws IOException niC ;WK
{ 6<1 2j7
oSavedFile = new RandomAccessFile(sName,"rw"); C0C2]xx{
this.nPos = nPos; Hi%)TDfv
oSavedFile.seek(nPos); la4 #2>#WZ
} ;>hRj!
c"KN;9c,
!]f80z
public synchronized int write(byte[] b,int nStart,int nLen) Ey|{yUmU+
{ X* 4C?v
int n = -1; E? lK(C
try{ )j,Y(V$P
oSavedFile.write(b,nStart,nLen); aa2 vk)~
n = nLen; u00w'=pe)
} uB=DC'lkg
catch(IOException e) 8k{KnH
{ kB` @M>[
e.printStackTrace (); niA>afo
} #| pn,/
p!>5}f6
V8nz@
return n; h+rW%`B
} gmqA 5W~y
$UD$NSl
ayYl3
} 8n/8uRIR
)\KU:_l
!C(U9p. 0
/* hbdB67,
**SiteInfoBean.java 63E)RR_Lh
*/ VTUSM{TC
package NetFox; ++sbSl)Q
o2D;EUsNX
i>7]9gBm1q
public class SiteInfoBean { C2CR#b=)i
C{:U<q
EK.n $
private String sSiteURL; //Site's URL wg+[T;0S
private String sFilePath; //Saved File's Path pocXQEg$]
private String sFileName; //Saved File's Name &^`[$LtYd
private int nSplitter; //Count of Splited Downloading File U3jnH
}hE!0q~MfM
?bH`
public SiteInfoBean() f?r{Q
{//nSplitter的缺省值为5 SdF+b+P]
//default value of nSplitter is 5 ]u^ybW"
this("","","",5); ]SAGh|+xl
} Mtl`A'KQ/K
JXjH}C
NFyV02.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) PWeWz(]0Z4
{ OHwH(}H?
sSiteURL= sURL; PMi.)%++
sFilePath = sPath; ykRd+H-t
sFileName = sName; !UR3`Xk
this.nSplitter = nSpiltter; ![!,i\x
]Q,&7D Ah
e7y,zcbv
} @EURp
p1[|5r5Day
Lf:#koaC
public String getSSiteURL() O6vHo3k
{ )gz]F_
return sSiteURL; W9{i~.zo
} }~Do0XUH
9@?|rje9
?VCp_Ji
public void setSSiteURL(String value) DxD\o+:r
{ z0x^HDAeC
sSiteURL = value; qfdL *D
} ?^J%S,
k%8kt4\wn6
AQtOTT$
public String getSFilePath() y<*\D_J
{ GDs/U1[*
return sFilePath; h+7U'+|%A
} *%\Xw*\0
0$NzRPbH
wz@[rMf
public void setSFilePath(String value) #V)l>
{ y<~(}xsHh
sFilePath = value; 'SXLnoeTa
} "$b{EYq6
dKP| TRd
3sRI7g
public String getSFileName() EiP N44(
{ z:N?T0b(
return sFileName; Pqj\vdzx
} \ KsKb0sM
~}/_QlX` K
t0Lt+E|J
public void setSFileName(String value) v9!]/]U^
{ FjI1'Ah\
sFileName = value; <;@E .I\N
} 5!wjYQt3
7*%}=.
Z%b1B<u$
public int getNSplitter() *=]UWM~]
{ e|>@ >F]K
return nSplitter; JaR!9GVN7
} WRRR"Q$
r[^O 7
dtjb(*x
public void setNSplitter(int nCount) ug'^$geM
{ &h.?~Ri
nSplitter = nCount; "HwlN_PA
} Nx+5rp
} &LG|YvMY6
5E 9R+N
E$A=*-u
/* pAaNWm
**Utility.java 56u_viZ=8
*/ pV!WZUfg
package NetFox; ]GsI|se
] yWywa\
}[PC YnS
public class Utility { \IEuu^
V}~',o<m
e2>AL
public Utility() '#oH1$W]
{ KdzV^6K<c
yn20*ix{
dB QCr{7
} epG =)gd=8
V&/Cb&~Uw
//线程睡眠 -a"b:Q
public static void sleep(int nSecond) <xrya_R?
{ S)'&+HamI
try{ k!x`cp
Thread.sleep(nSecond); zz<o4bR
} 1=z\,~b
catch(Exception e) MX+gc$Y O
{ DK'S4%;Sp
e.printStackTrace (); U'Y,T$Q
} JW=q'ibR
} NF-@Q@
W@%g_V}C*
//日志 ^X"x,8}&V
public static void log(String sMsg) v-"nyy-&Z
{ EN,}[^Z
System.err.println(sMsg); +CXq41g"c
} LWN9 D
Q)8I(*
~EvGNnTL
public static void log(int sMsg) ; 0M"T[c
{ ; 3sjTqD
System.err.println(sMsg); RX^Xtc"
} Ysw&J}6e
} g&8-X?^Q
PeLzZ'$D
/#q6.du
/* ^V]IPGV
**TestMethod.java ~0}d=d5g
*/ 6['o^>\}f
package NetFox; MlW*Tugg
8KKhD$
vWL|vR
public class TestMethod { ~8-xj6^
5v=e(Ph+
:oiHf:
public TestMethod() b dC
{ ///xx/weblogic60b2_win.exe x`2du/ C
try{ FMWM:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k/BlkjlNE
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _?eT[!oO8
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7mtg
fileFetch.start(); :YLurng/]
} $s 'n]]Wq
catch(Exception e){e.printStackTrace ();} fP$rOJ)P
:-(qqC:
8q:# '
} WSGho(\
9w=[}<E
#qK5i1<
public static void main(String[] args) \BO6.;jA
{ HK%W7i/k@
new TestMethod(); 'T;;-M3*
} zw iS%-F
} p\.IP2+c
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