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)); "2>_eZ#b
} MB!$s_~o#L
for(int i=0;i<nEndPos.length-1;i++) 5o2|QL
{ ,%U'>F?
nEndPos = nStartPos[i+1]; .?LP$O=
} Xw]L'+V=
nEndPos[nEndPos.length-1] = nFileLength; 1zWEK]2.R
} We:b1sZR
} -=VGXd
I1fUV72
BjAmM*k
//启动子线程 U`)o$4Bq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KpSho<
for(int i=0;i<nStartPos.length;i++) ]x^v;r~
{ 6+ C7vG`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~spfQV~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [fl^1!3{
nStartPos,nEndPos,i); xSL%1>MrN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lbnH|;`$]m
fileSplitterFetch.start(); &'A8R;b}-?
} +X4/l"|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m6YDyQC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5/C#*%EH'
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", oa:30@HSb
nEndPos = " + nFileLength); 2Pic4Z
// fileSplitterFetch[nPos.length-1].start(); Mhiz{Td
~-zch=+u
V^E.9fs,
//等待子线程结束 *WK0dn
//int count = 0; pipqXe
//是否结束while循环 $|n#L6k
boolean breakWhile = false; 3%DDN\q\u
" twq#Alx
+"F9yb
while(!bStop) ~"8)9&
{ A-5'OI
write_nPos(); * vW#XDx
Utility.sleep(500); yp\sJc`
breakWhile = true; CI~ll=9`
L6f$ID:
.wJv_
for(int i=0;i<nStartPos.length;i++) hkoCbR0}8
{ ZhYOz
if(!fileSplitterFetch.bDownOver) yVl?gGgh
{ ;.|).y1/`
breakWhile = false; }.74w0~0^
break; FCPiU3
} (|_N2R!
} 2#t35fU
if(breakWhile) w//L2.
break; 1k?k{Ri
tC4 7P[b
C">w3#M%
//count++; a[A9(Ftn
//if(count>4) EH~XN9b
// siteStop(); HL34pmc
} I'>r
g1B[RSWv
'/v@q]!
System.err.println("文件下载结束！"); V]qv,>
} kSq1Q#Bxq
catch(Exception e){e.printStackTrace ();} Sz#dld Mz
} U6 $)e.FO
U3 y-cgE
^L +@oS
//获得文件长度 y;1l].L
public long getFileSize() 8e*1L:oB!
{ flzHZH
int nFileLength = -1; K3On8
try{ "*N=aHsj
URL url = new URL(siteInfoBean.getSSiteURL()); Y1Sfhs)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T~JE.Y3B3
httpConnection.setRequestProperty("User-Agent","NetFox"); WC *e#QP
'980.
W*/0[|n*
int responseCode=httpConnection.getResponseCode(); w0!4@
if(responseCode>=400) E[E7GsmqV
{ `/\Z{j0_
processErrorCode(responseCode); DU=rsePWE
return -2; //-2 represent access is error R0_O/o+{
} QGpAG#M9?
568qdD`PS
41Htsj
String sHeader; mZ^ev;
L6E8A?>5rD
dzn[4
for(int i=1;;i++) -`<KjS
{ UthH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); afNqK~
//Utility.log(in.readLine()); *D6X&Hg&5
sHeader=httpConnection.getHeaderFieldKey(i); rj> _L
if(sHeader!=null) 8O_0x)X
{ 5y%-K=d
if(sHeader.equals("Content-Length")) Hd9vS"TN]
{ 8,m3]Lg
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %}0B7_6B+@
break; -T+7u
} qTD^Vz V
} ]31UA>/TI
else Ccx1#^`
break; 67{>x[
} eg$y,Tx
} `7mRUDz
catch(IOException e){e.printStackTrace ();} +M/1,&
catch(Exception e){e.printStackTrace ();} g&oAa;~o
GoTJm}[NP
:\<D q71
Utility.log(nFileLength); r#;GVJR6
H@%Y"iIUP
W{z{AxS
return nFileLength; Yl#|+xYA5[
} jJOs`'~Q\
4UV<Q*B\F
d?Y|w3lB
//保存下载信息（文件指针位置） U81--'@y
private void write_nPos() 4Cn% h)w
{ 4>I >y@^
try{ ^w(~gQ6|mP
output = new DataOutputStream(new FileOutputStream(tmpFile)); okv`+VeA
output.writeInt(nStartPos.length); <yq kJ
for(int i=0;i<nStartPos.length;i++) ]`,jaD
{ ~R!M.gY[rK
// output.writeLong(nPos); /-v6jiM
output.writeLong(fileSplitterFetch.nStartPos); |{en){:
output.writeLong(fileSplitterFetch.nEndPos); .\6q\7Ej
} eKw!%97>
output.close(); #lld*I"d
} Un[ 0or
catch(IOException e){e.printStackTrace ();} 9KgGK cy%
catch(Exception e){e.printStackTrace ();} Gi=s|vt
} Jv+N/+M47
yy*8Aw}
jFr[T
//读取保存的下载信息（文件指针位置） 1O{(9nNj
private void read_nPos() xS>d$)rIj
{ 2uln)]
try{ uz%<K(:Ov
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7yM"G$
int nCount = input.readInt(); |2t1m 6\j
nStartPos = new long[nCount]; QO&{Jx.^[
nEndPos = new long[nCount]; _hz}I>G@B
for(int i=0;i<nStartPos.length;i++) m2|%AD
{ 6 J B"qd
nStartPos = input.readLong(); &uMx*TTY
nEndPos = input.readLong(); d[7B,l:RN
} Vw>AD<Rl
input.close(); !`h^S)$
} >nqCUhS
catch(IOException e){e.printStackTrace ();} Jdc{H/10
catch(Exception e){e.printStackTrace ();} NZW)$c'
} .%x%b6EI
CNkI9>L=W`
2f8\Osn>m
private void processErrorCode(int nErrorCode) }\$CU N
{ BD.>aAi!
System.err.println("Error Code : " + nErrorCode); b$W~w*O
} d(X/N2~g
HkL`- c0
"z6xS;
//停止文件下载 E'ay @YAp
public void siteStop() HZJ)q`1E
{ %UXmWXF4$
bStop = true; P]mJ01@'
for(int i=0;i<nStartPos.length;i++) mY1Gm|
fileSplitterFetch.splitterStop(); ]o<&Q52|
M8{J
{IgLH`@
} MX)mm^A
} ]I<w;.z
//负责部分文件的抓取 u"s@eN
**FileSplitterFetch.java `Hp=1a
*/ gmW-#.
package NetFox; m*f"Y"B.1I
=euMOs
.X](B~\!
import java.io.*; 6a!b20IZh
import java.net.*; V<&^zIJUR
"pInb5F
089 <B& <
public class FileSplitterFetch extends Thread { ]p-xds#d
/a7N:Z_Bz
xMr=tU1C
String sURL; //File URL 2K VX
long nStartPos; //File Snippet Start Position o^8Z cN>
long nEndPos; //File Snippet End Position 6F8TiR&
int nThreadID; //Thread's ID vi;yT.
boolean bDownOver = false; //Downing is over _X]\#^UiO2
boolean bStop = false; //Stop identical 3o^~6A
FileAccessI fileAccessI = null; //File Access interface ~LF1$Cai
rf=oH }
%F2T`?t:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 57jDsQAj
{ %)#yMMhR
this.sURL = sURL; UY}EW`$#m
this.nStartPos = nStart; Qu_=K_W
this.nEndPos = nEnd; !~_6S*~
nThreadID = id; qF3s&WI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l0K_29^
} 'TO/i:{\
L}UrI&]V$:
EL^j}P
public void run() 3S=$ng
{ +|6E~#zklY
while(nStartPos < nEndPos && !bStop) Sah!|9
{ 9 Eqv^0u
%{B4M#~
U7xKu75G1
try{ %zYTTPLZ
URL url = new URL(sURL); &~'^;hy=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cXIuGvE&=
httpConnection.setRequestProperty("User-Agent","NetFox"); '>:%n
String sProperty = "bytes="+nStartPos+"-"; t;b1<TLn0
httpConnection.setRequestProperty("RANGE",sProperty); _+ERX[i
Utility.log(sProperty); nU23D@l
C {G647
Zjn![
InputStream input = httpConnection.getInputStream(); #SR )tU
//logResponseHead(httpConnection); 1B`JvNtd
tpQ8 m(
j)mi~i*U
byte[] b = new byte[1024]; xgJyG.?
int nRead; G7k.YtW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \=j|ju3
{ :a*F>S!
nStartPos += fileAccessI.write(b,0,nRead); LM*m>n*
//if(nThreadID == 1) :Tdl84
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +a|u,'u
} asL!@YE
>a)6GZ@
JpZ3T~Wrf
Utility.log("Thread " + nThreadID + " is over!"); 0IxHB|^$
bDownOver = true; 98Im/v
//nPos = fileAccessI.write (b,0,nRead); SD.c9
} K_}81|=
catch(Exception e){e.printStackTrace ();} ^:2>I$
} &`}ACTY'P
} /rnP/X)T
R_duPaWc@
fO}Y$y\q
//打印回应的头信息 P,bis7X.
public void logResponseHead(HttpURLConnection con) _Kv;hR>
{ IFkU8EK&B
for(int i=1;;i++) _/5xtupxE
{ keS%w]87
String header=con.getHeaderFieldKey(i); l<p6zD$l
if(header!=null) &t@|/~%[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t<yOTVah
Utility.log(header+" : "+con.getHeaderField(header)); 6Z!OD(/e
else rp!>rM] s
break; V&R_A~<T
} fvM|Jb
} vqRW^>~-B
Q@- h
k-8$43
public void splitterStop() WO+_|*&
{ 4p]hY!7
bStop = true; x<>In"QV
} q&@q/9kz
.xg, j{%(
K~ VUD(
} _j?/O)M c
}>?"bcJ
k2DBm q;
/* |\/V1
**FileAccess.java !z_VwZ#,
*//文件访问(定位，写) 5uD'Kd$H
package NetFox; J-Wphc!m
import java.io.*; 3ms{gZbw
AjMx\'(C
Y-G;;~
public class FileAccessI implements Serializable{ K2ry@haN
8p.O rdp
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ek]CTUl*
RandomAccessFile oSavedFile; d1/uI^8>
long nPos; Q);^gV
/Avl&Rd
E{E%nXR)
public FileAccessI() throws IOException :\,3=suWq
{ X-J<gI(Y
this("",0); Ng1uJa[k!d
} XkuZ2(
yWZ%|K~$
qb$f,E[
public FileAccessI(String sName,long nPos) throws IOException j~`rc2n%
{ =@go;,"
oSavedFile = new RandomAccessFile(sName,"rw"); KHt.g`1:R
this.nPos = nPos; `+EjmY
oSavedFile.seek(nPos); pYaq1_<+
} YJ~3eZQ
qJLtqv
pax;#*QcQ
public synchronized int write(byte[] b,int nStart,int nLen) C]DvoJmBs
{ @G0j/@v
int n = -1; uNG?`>4>
try{ \&5t@sC
oSavedFile.write(b,nStart,nLen); CDgu`jj%]
n = nLen; %yP*Vp,W
} ^FN(wvqb8
catch(IOException e) \F8*HPM=*
{ $K*&Wdo
e.printStackTrace (); tJ@5E^'4
} \k)(:[^FY
|csR"DOqz
mdPEF)-
return n; PV/SzfvIq
} Mwd(?o
o;2QZ"v
~$Pz`amT|
} FT.;}!"l
Oj^qh+r
J,]U"+;H
/* 5<KY}
**SiteInfoBean.java rg{|/ ;imT
*/ |HMpVT-;j
package NetFox; Z4@GcdZ
*WpDavovyB
i& ybvTl
public class SiteInfoBean { =)9@rV&~
1b-_![&]1
h?ZxS
private String sSiteURL; //Site's URL x"QZ}28(t
private String sFilePath; //Saved File's Path FZ^j|2.L*
private String sFileName; //Saved File's Name yZ]u{LJS
private int nSplitter; //Count of Splited Downloading File JJ$q*
9Lv"|S`5W_
$C8nPl' 7
public SiteInfoBean() Wa+q[E
{//nSplitter的缺省值为5 V_Oj?MMpn
//default value of nSplitter is 5 >gFEA0-
this("","","",5); %wuD4PRK
} ]EZiPW-uy
MUfhk)"
@>sZ'M2mq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1O,<JrE+-
{ V,qc[*_3
sSiteURL= sURL; mh=YrDU+L
sFilePath = sPath; 2RC|u?+@
sFileName = sName; P\R#!+FgW8
this.nSplitter = nSpiltter; NLA/XZ
q2C._{ 0'
`c~J&@|
} ;VAHgIpx;
oWo/QNw9
&KS*rHgt?
public String getSSiteURL() !+# pGSk
{ J"Z=`I)KON
return sSiteURL; 5x:dhkW
} @fSBW+
=1'vXPv`
fNnemn@>
public void setSSiteURL(String value) @XL5$k[Y
{ d`+@ _)ea
sSiteURL = value; n^2p jTkl
} r1)@ 7Nt
BQfq]ti
t/TWLhx/
public String getSFilePath() +__PT4ps
{ ^<VJ8jk<
return sFilePath; [|!A3o
} K7CrRT3>6
IDIok~B=e
;9rS[$^$O
public void setSFilePath(String value) "bC1dl<
{ k6?;D_dm
sFilePath = value; [R~`6
} nPU=n[t8O
J*} warf&
s}3`%?,6y
public String getSFileName() L d;))e
{ qXw^y
return sFileName; Ob#d;F
} uVn"'p-
OmR)W'
X5gI'u
public void setSFileName(String value) exHg<18WSe
{ y]e[fZ`L
sFileName = value; R]! [h
} -)p S\$GC
rV0X*[]J>
t/57LjV
public int getNSplitter() }pMd/|A,
{ 9cwy;au
return nSplitter; V|n}v?f_q
} ?8GggJC
p&nPzZQL(
;"K;D@xzh]
public void setNSplitter(int nCount) %7y8a`}
{ /5$;W'I
nSplitter = nCount; /)<x<7FKW
} ym=7EY?o
} Y%1 94fY$
-0>gq$/N=^
+338z<'Z!
/* }@XokRk
**Utility.java JE<w7:R&
*/ Sbp].3^j
package NetFox; W:gpcR]>
CVy\']
nde_%d$
public class Utility { W Y]
+\_c*'K>
6B=: P3Y
public Utility() h7"c_=w+
{ j*'+f~A
p"UdD
L<62-+e`
} o<8('j
e>] gCa
//线程睡眠 =+z+`ot
public static void sleep(int nSecond) Z.l4<
{ S<Os\/*
try{ w$##GM=Tq
Thread.sleep(nSecond); A 6IrA/b
} bQlvb
catch(Exception e) g]Jt (aYK
{ /L yoTBG
e.printStackTrace (); BtA_1RO
} Rl/5eE8
} 5w+KIHhN|
tg%#W`
//日志 @/,:". SM
public static void log(String sMsg) ouE/\4'NB
{ wr-/R"fX
System.err.println(sMsg); [Xyu_I-c
} U5RLM_a@M
>_J9D?3S
SIridZ*%
public static void log(int sMsg) $Vp*,oRL
{ !*eDT4a
System.err.println(sMsg); Oo0SDWI`(
} !7hjA=0
} 4'wbtE|
qeUT]* w
[p+-]V
/* C==yl"w
**TestMethod.java YWFq&II|Z
*/ uo8[,'
package NetFox; omMOA
Cvp!(<<gK
ZccvZl ;b
public class TestMethod { 9?XQB%44
4=~+Bz
n "bii7h
public TestMethod() H[_i=X3-~
{ ///xx/weblogic60b2_win.exe mPL0s
try{ >I@VHl O
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?Xl;>}zj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U EjP`
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;aN_!! r
fileFetch.start(); 7 'q *(v
} QdrZi.qKH
catch(Exception e){e.printStackTrace ();} smUSR4VK
/rIyW?& f
lQM&q
} :N^+!,i
zub"Ap3
b} 0G~oLP
public static void main(String[] args) rez)$
{ V1&qgAy~
new TestMethod(); L</k+a?H!
} RY .@_{
} {vq| 0t\-
点击下载更多相关资料