社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 10065阅读
  • 0回复

http断点续传简单实现(java)

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
/* E_rI?t^  
**SiteFileFetch.java C[cbbp  
*/ "S[450%  
package NetFox; 9c bd~mM{  
import java.io.*; h,:m~0gmj  
import java.net.*; ]h`&&Bqt  
LE Nq_@$  
mY|)KJ  
public class SiteFileFetch extends Thread { P}}* Q7P  
l:~/<`o  
J3V= 46Yc  
SiteInfoBean siteInfoBean = null; //文件信息Bean fUWG*o9  
long[] nStartPos; //开始位置 /xBb[44z8  
long[] nEndPos; //结束位置 h8q[1"a:  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 dlh)gp;  
long nFileLength; //文件长度 6GlJ>r+n  
boolean bFirst = true; //是否第一次取文件 RMV/&85?y  
boolean bStop = false; //停止标志 6yG^p]zZ  
File tmpFile; //文件下载的临时信息 g{)dP!}  
DataOutputStream output; //输出到文件的输出流 ^LnTOdAE  
B3`5O[ 6  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) {lzWrUGO  
public SiteFileFetch(SiteInfoBean bean) throws IOException gx/,)> E.  
{ =ZznFVJ`={  
siteInfoBean = bean; ,<_A2t 2  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Evq IcZ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); J[|y:N  
if(tmpFile.exists ()) y-b%T|p9  
{ 1s&zMWC  
bFirst = false; u/0h$l  
read_nPos(); WDYeOtc  
} NN{?z!  
else /U*C\ xMm  
{ 9<?M8_  
nStartPos = new long[bean.getNSplitter()]; W+c<2?d:  
nEndPos = new long[bean.getNSplitter()]; x j)F55e?  
} O`kl\K*R7  
3*XNV  
}"H,h)T  
R%WCH?B<}  
} r|8d 4  
cl3K<'D  
a.\:T,cP>  
public void run() 3ZPWze6  
{ jRlYU`?  
//获得文件长度 7aRi5  
//分割文件 !*&V- 4  
//实例FileSplitterFetch ?p{Nwl#  
//启动FileSplitterFetch线程 y14;%aQN  
//等待子线程返回 6Pnjmw.HV  
try{ 1-uxC^u?|#  
if(bFirst) 76Cl\rV  
{ :S83vE81WK  
nFileLength = getFileSize(); ~Ffo-Nd-  
if(nFileLength == -1) :RTC!spy  
{ 4Z=_,#h4.  
System.err.println("File Length is not known!"); >2)OiQ`zg  
} #Vt%@* i  
else if(nFileLength == -2) Jt<_zn_FG  
{ NNR`!Pty  
System.err.println("File is not access!"); | j`@eF/"  
} 8'[7 )I=  
else ~W'{p  
{ 9L?.m&  
for(int i=0;i<nStartPos.length;i++) 8 >EWKI9  
{ <al(7  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =o(5_S.u;  
} 9&2O 9Nz6  
for(int i=0;i<nEndPos.length-1;i++) 8 ^2oWC#U(  
{ lv<*7BCp  
nEndPos = nStartPos[i+1]; 0S_~\t  
} d L 1tl  
nEndPos[nEndPos.length-1] = nFileLength; 4[r0G+  
} ~H_/zK6e  
} nNV'O(x}  
=:Fc;n>c<K  
Fnv;^}\z  
//启动子线程 %N6A+5H  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~ 'cmSiz-  
for(int i=0;i<nStartPos.length;i++) ~$cV: O7  
{ Lx1FpHo  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KP^V>9q  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `2WFk8) F  
nStartPos,nEndPos,i); )[6U^j4  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xC:L)7#aw  
fileSplitterFetch.start(); qJs<#MQ2  
} #U4F0BdA  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 286;=rN]*  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L#?Ek-  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 4jM Fr,  
nEndPos = " + nFileLength); 6:5I26  
// fileSplitterFetch[nPos.length-1].start(); UgN u`$m+  
{X+3;&@  
mHTXni<!  
//等待子线程结束 ~ "H,/m%2o  
//int count = 0; {SPq$B_VR  
//是否结束while循环 Oc#syfO  
boolean breakWhile = false; tjGn|+|k  
ItVWO:x&v  
%6,SKg p  
while(!bStop) &X ):4  
{ -H@:*  
write_nPos(); d#Y^>"|$.  
Utility.sleep(500); P>C~ i:4n  
breakWhile = true; 29"'K.r  
W~; `WR;.  
Lc,Pom  
for(int i=0;i<nStartPos.length;i++) ~9]hV7y5C  
{ ;O6;.5q&  
if(!fileSplitterFetch.bDownOver) |Nn)m  
{ RDi]2  
breakWhile = false; Dlae;5 D  
break; AaOu L,l  
} F?*-4I-  
} ,/%=sux  
if(breakWhile) e0zq1XcZ  
break; wLH>:yKUU  
bKY7/w<dP  
gIa+5\qYY  
//count++; }Yzco52  
//if(count>4) )JLdO*H  
// siteStop(); x%m%_2%Z  
} Egp/f|y  
Y|f[bw  
mt{nm[D!Xp  
System.err.println("文件下载结束!"); Qf+\;@  
} y/cvQY0pU  
catch(Exception e){e.printStackTrace ();} c /HHy,  
} ?k&Vy  
 SI-qC  
)e+>w=t  
//获得文件长度 ^z IW+:  
public long getFileSize() R6.hA_ih  
{ C.yQ=\U2  
int nFileLength = -1; HGs $*  
try{ @/.;Xw]  
URL url = new URL(siteInfoBean.getSSiteURL()); 6+|do+0Icg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f!uwzHA`?  
httpConnection.setRequestProperty("User-Agent","NetFox"); TH&U j1  
_Xc8Yg }`  
Y-_`23x`  
int responseCode=httpConnection.getResponseCode(); R6Km\N  
if(responseCode>=400) m@2QnA[ 4  
{ Ts[_u@   
processErrorCode(responseCode); kR-SE5`Jk  
return -2; //-2 represent access is error Nho>f  
} L^2%1GfE{  
#ym'AN  
>V?eog%~  
String sHeader; -`kW&I0  
iDp)FQ$  
+T1pJ 89P  
for(int i=1;;i++) H9`)BbR  
{ HZC"nb}r4  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); XK3tgaH  
//Utility.log(in.readLine()); XkE`U5.  
sHeader=httpConnection.getHeaderFieldKey(i); JV^=v@Z3  
if(sHeader!=null) rNWw?_H-H(  
{ 5h=}j  
if(sHeader.equals("Content-Length")) %~H-)_d20  
{ DFB@O|JL  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); WUe{vV#S'0  
break; kW Ml  
} p Z|V 3  
} x_N'TjS^{  
else (l~AV9!m:  
break; &tLgG4pd  
} #uG%j  
} Eex~xiiV  
catch(IOException e){e.printStackTrace ();} x:NY\._  
catch(Exception e){e.printStackTrace ();} 0WW2i{7`U  
UT~4x|b:O  
[I,Z2G,Jb  
Utility.log(nFileLength); QC OM_$y  
{tuYs:  
A Ru2W1g  
return nFileLength; 2 /\r)$ 2i  
} ArI2wM/v  
~F|+o}a `  
A@!qv#'  
//保存下载信息(文件指针位置) r[`9uVT/  
private void write_nPos() w7.V6S$Ga  
{ +K:Dx!9  
try{ bQg:zww  
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ha0M)0Anv  
output.writeInt(nStartPos.length); #C74z$  
for(int i=0;i<nStartPos.length;i++) /!yU !`bY  
{ OhQgF  
// output.writeLong(nPos); %op**@4/t\  
output.writeLong(fileSplitterFetch.nStartPos); Q^9_' t}X  
output.writeLong(fileSplitterFetch.nEndPos); )Pa'UGY  
} n`B:;2X,  
output.close(); Ct<udO  
} H7&8\ FNa  
catch(IOException e){e.printStackTrace ();} *MhRW,=  
catch(Exception e){e.printStackTrace ();} z;,u}u}aI  
} c \J:![x  
 ul6]!Iy  
qdJ=lhHM}  
//读取保存的下载信息(文件指针位置) 36&e.3/#  
private void read_nPos() F4-$~ v@  
{ +aCv&sg  
try{ w>s,"2&5J  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .GP T!lDc  
int nCount = input.readInt(); YNyk1cE  
nStartPos = new long[nCount];  j|DsG,  
nEndPos = new long[nCount]; T"}5}6rSG  
for(int i=0;i<nStartPos.length;i++) X Swl Tg  
{ ?|\ER#z  
nStartPos = input.readLong(); [\98$BN  
nEndPos = input.readLong(); ed{ -/l~j  
} (&Kk7<#`  
input.close(); .]Y$o^mf  
} ;C9_?u~#  
catch(IOException e){e.printStackTrace ();} 4<w.8rR:A  
catch(Exception e){e.printStackTrace ();} JQ_sUYh~3  
} +;(c:@>@,  
,GhS[VJjR  
,hm\   
private void processErrorCode(int nErrorCode) X6w6%fzOH>  
{ I3{PZhU.  
System.err.println("Error Code : " + nErrorCode); CAig ]=2'  
} Wq D4YGN  
\j}ZB<.>  
R6<X%*&%  
//停止文件下载 \_VA 50  
public void siteStop() j;+b0(53  
{ $lfn(b,  
bStop = true; aB2F C$z  
for(int i=0;i<nStartPos.length;i++) b4%??"&<Y  
fileSplitterFetch.splitterStop(); 2. NN8PPD"  
DZ 3wCLQtK  
V# }!-Xj  
} }1L4 "}L.  
} ,B*EVN  
//负责部分文件的抓取 [: n'k  
**FileSplitterFetch.java +5g_KS  
*/ <Uk}o8E  
package NetFox; P-9)38`5  
kr^P6}'  
z>1Pz(  
import java.io.*; T$)^gHS  
import java.net.*; r..iko]T  
L:$ ,v^2  
U*rcd-@  
public class FileSplitterFetch extends Thread { Y #ap*  
:DK {Vg6  
bI7Vwyz  
String sURL; //File URL P[G)sA_"  
long nStartPos; //File Snippet Start Position kf\PioD8  
long nEndPos; //File Snippet End Position l?v86k  
int nThreadID; //Thread's ID jodIv=C  
boolean bDownOver = false; //Downing is over '6nA F  
boolean bStop = false; //Stop identical T8?Ghbn  
FileAccessI fileAccessI = null; //File Access interface 0mYXv4 <  
Di,^%  
P8OaoPj  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :_`F{rDB  
{ \S `:y?[Y  
this.sURL = sURL; y;m|  
this.nStartPos = nStart; "=HA Y  
this.nEndPos = nEnd; B {n,t}z  
nThreadID = id; w8")w*9Lmg  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9d0@wq.  
} =g7x' kN  
nSDMOyj+  
zH72'"w  
public void run() *?@?f&E/  
{ ]\-A;}\e  
while(nStartPos < nEndPos && !bStop) ch*8B(:  
{ &@X<zWg  
;>%r9pz ~  
rK 8lBy:<  
try{ nmee 'oEw  
URL url = new URL(sURL); ].avItg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <)C#_w)-  
httpConnection.setRequestProperty("User-Agent","NetFox"); np|Sy;:  
String sProperty = "bytes="+nStartPos+"-"; @Myo'{3vF  
httpConnection.setRequestProperty("RANGE",sProperty); YH}'s>xZz  
Utility.log(sProperty); nUaJzPl  
'&P%C" 5  
)rIwqUgp6\  
InputStream input = httpConnection.getInputStream(); j.[.1G*("  
//logResponseHead(httpConnection); zF`0J  
&Q/W~)~  
L8@f-Kk  
byte[] b = new byte[1024]; c`)\Pb/O  
int nRead; KWbI'}_z  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;HfmzY(  
{ ~p6 V,Q  
nStartPos += fileAccessI.write(b,0,nRead); u4cnE"  
//if(nThreadID == 1) &C5_g$Ma.Z  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B6+khuG(  
} +zqn<<9  
7uqzm  
Uk[b|<U-`d  
Utility.log("Thread " + nThreadID + " is over!"); 3oj' ytxN  
bDownOver = true; J/`<!$<c  
//nPos = fileAccessI.write (b,0,nRead); ^do9*YejX;  
} f#>,1,S  
catch(Exception e){e.printStackTrace ();} tH@Erh|%  
} #Qw0&kM7I  
} .fqN|[>  
5;Czu(iH$  
nQZx= JK  
//打印回应的头信息 +%z> H"J.  
public void logResponseHead(HttpURLConnection con) Hzm:xg  
{ @,j*wnR  
for(int i=1;;i++) @f>-^  
{ '`[&}R  
String header=con.getHeaderFieldKey(i); oi7@s0@  
if(header!=null) E:_ZA  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n t;m+by  
Utility.log(header+" : "+con.getHeaderField(header)); 3)wN))VBX  
else b<[Or^X ]  
break; *uRBzO}  
} k!j5tsiR  
} ^]Y> [[  
l+K'beP  
=osk+uzzG  
public void splitterStop() W\$`w  
{ H064BM  
bStop = true; /|m2WxK)  
} VOsR An/N  
IxN9&xa  
XAKs0*J>  
} f1RWP@iar  
;vR4XHl|  
un"Gozmt5  
/* #6aW9GO  
**FileAccess.java 4}baSV  
*//文件访问(定位,写) (62"8iD6  
package NetFox; w>&aEv/f  
import java.io.*; !<8W {LT  
' ,wFTV&  
G^|:N[>B  
public class FileAccessI implements Serializable{ .[KrlfI  
m]0;"jeL  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A/$QaB,x  
RandomAccessFile oSavedFile; J$DE"| -  
long nPos; ;W )Y OT  
ij`w} V  
MTh<|$   
public FileAccessI() throws IOException A0s ZOCky  
{ 2eS~/Pq5=i  
this("",0); =!A_^;NQf  
} %g$o/A$  
^$jb7HMObI  
Lnl(2xD  
public FileAccessI(String sName,long nPos) throws IOException K hR81\  
{ T@B/xAq5!  
oSavedFile = new RandomAccessFile(sName,"rw"); /N10  
this.nPos = nPos; x_Y!5yg E  
oSavedFile.seek(nPos); H [\o RId  
} oG?Xk%7&\  
_Kf%\xg  
3AtGy'NTp  
public synchronized int write(byte[] b,int nStart,int nLen) q-2Bt,Y  
{ ] IQ&>z}<  
int n = -1; hp X9[3  
try{ Hyl%mJ  
oSavedFile.write(b,nStart,nLen); z (wc0I  
n = nLen; Xza(k  
} (*'f+R`$  
catch(IOException e) &-6Gc;f8  
{ *I.f1lz%*  
e.printStackTrace (); ORw,)l  
} S!CC }3zw  
WIxy}3_to  
qS$Ox?Bw#u  
return n; :J@ gmY:C  
} V!A~K   
`5.'_3  
prF%.(G2)  
} =z69e%.  
` p-cSxR_  
%)W2H^  
/* G `61~F%  
**SiteInfoBean.java :Yh+>c}N  
*/ UKvWJnz  
package NetFox; xGg )Y#  
- %h.t+=U  
Qbn"=n2  
public class SiteInfoBean { J/aC}}5D  
CYP q#rd  
.@U@xRu7|  
private String sSiteURL; //Site's URL i$G@R %  
private String sFilePath; //Saved File's Path \V8PhO;j  
private String sFileName; //Saved File's Name @o _}g !9=  
private int nSplitter; //Count of Splited Downloading File *vxk@ `K~  
mxC;?s;~  
b5vC'B-!  
public SiteInfoBean() v>)"HL"XG  
{//nSplitter的缺省值为5 *)T^Ch D,  
//default value of nSplitter is 5 #OD/$f_  
this("","","",5); ,m:.-iy?  
} (Zrj_P`0[  
0&|\N ? 8_  
E,U+o $  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kJsN|=  
{ & G4\2l9  
sSiteURL= sURL; mSF(q78?  
sFilePath = sPath; E A1?)|}n  
sFileName = sName; d#4**BM  
this.nSplitter = nSpiltter; 0@iY:aF  
IY\5@PVZ  
b9HtR-iR;  
} 6j]0R*B7`Q  
m8hk:4Ae  
g7`LEF <A  
public String getSSiteURL()  w``ST  
{ <)c)%'v  
return sSiteURL; 9IfmW^0  
} ;))+>%SGCt  
c9u`!'g`i  
| rtD.,m   
public void setSSiteURL(String value) oIzj,v8$  
{ y I  
sSiteURL = value; ,f'CD{E  
} 9F;>W ET  
6}Ci>_i4#  
37.S\ gO]  
public String getSFilePath() K;H&n1  
{ YfKdR"i+.  
return sFilePath; 8^+%I/S$  
} qWPkT$ u  
rcG"o\g@+  
,m|h<faZL  
public void setSFilePath(String value) u^I|T.w<r6  
{ j-}O0~Jz  
sFilePath = value; <^jQo<kU  
} '4Bm;&6M  
EUX\^c]n  
O;jrCB  
public String getSFileName() aSQ#k;T[  
{ $Sip$\+*  
return sFileName; LCKV>3+_#  
} i3mcx)d@H  
 SRDp*  
p%=u#QNi  
public void setSFileName(String value) )}Kf=  
{ #r\4sVg  
sFileName = value; .|fH y  
} 4!yzsPJL  
`mJ6K&t$<  
j>"@,B g*  
public int getNSplitter() J<h $ wM  
{ E4/Dr}4  
return nSplitter; 2eY_%Y0  
} flbd0NB  
;$wVu|&  
>SHhAEF  
public void setNSplitter(int nCount) ul>3B4  
{ ?1 4{J]H4  
nSplitter = nCount; K Z91-  
} n 0L^e  
} S|N_o   
})Vi  
E*K;H8}s  
/* _A9AEi'.  
**Utility.java z46~@y%k  
*/  d{3QP5  
package NetFox; jm/`iXnMf  
`1fY)d^ZS  
e6$WQd`O  
public class Utility { y_-0tI\J  
o 3P${Rq  
h3 }OX{k  
public Utility() ?%[@Qb=2  
{ BW*rIn<?G  
Lnl=.z`jK  
T:yE(OBf  
} Eo]xNn/g  
v PG},m~-  
//线程睡眠 4>e&f&y~  
public static void sleep(int nSecond) +',S]Edx  
{ y766; X:J  
try{ =GMkR+<)  
Thread.sleep(nSecond); .}~_a76  
} v`Oc,  
catch(Exception e) c,+:i1IAy  
{ c 3)jccWTc  
e.printStackTrace (); y}ev ,j  
} c4eBt))}V  
} T+H!_ky`A  
.4!=p*Y  
//日志 )zdQ1&@  
public static void log(String sMsg) Bn&ze.F  
{ cIOlhX@  
System.err.println(sMsg); M!D3}JRm  
} [/41% B2  
/"Uqa,{  
R8Fv{7]c  
public static void log(int sMsg) =MDys b&:  
{ ],Do6 @M-  
System.err.println(sMsg); ope^~+c~\  
} ~dTrf>R8M  
} z_4J)?3  
e8?jmN`2  
@Z:l62l=bE  
/* 6A+nS=  
**TestMethod.java mtcw#D  
*/ T!)(Dv8@F  
package NetFox; {q^[a-h>  
i2SR{e8:GF  
H9Q&tl9  
public class TestMethod { O5T{eBo\  
p}U ~+:v  
Yufc{M00  
public TestMethod() $suzW;{#  
{ ///xx/weblogic60b2_win.exe -;WGS o  
try{ B>P{A7Q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }y gD3:vN7  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tJ$_lk ~6q  
SiteFileFetch fileFetch = new SiteFileFetch(bean); &E5g3lf  
fileFetch.start(); 'c$+sp ?  
} %YqEzlzF  
catch(Exception e){e.printStackTrace ();} p947w,1![  
N6i Q8P -  
R%[ c;i  
} ,/|T-Ka  
m#\ dSl}  
bq0zxg%  
public static void main(String[] args) UH"%N)[  
{ Em~>9f ?Q(  
new TestMethod(); }`m/bgtFX  
} Ao&"r[oJSv  
} YNsJZnGr8#  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
10+5=?,请输入中文答案:十五